Advice on Upskilling - by Justin Skycak

ISBN:
Date read: 2025-10-09
How strongly I recommend it: 8/10
(See my list of 430+ books, for more.)

Go to the Amazon page for details and reviews.

Super motivating book about effective learning and improvement. He’s a math, memory, and weightlifting expert from justinmath.com and MathAcademy.com, so the advice leans that way a bit, but applies to anything you want to learn. This book is not yet published but free here: https://www.justinmath.com/files/advice-on-upskilling.pdf

my notes

Build a habit with some less effective but more enjoyable form of practice.
Optimize for fun at the beginning to help you build a habit.
Start simple, whatever gets the ball rolling.
It will grow on you and seep into your identity
Procrastinating builds up the dread.
Just getting started makes it dissipate.
Once you’ve got a good habit going, do everything you can to protect it.

Hardcore skills are always the answer.
People want to make a big impact on the world and in their own lives.
But desire is not enough.
You can’t do anything big unless you have big skills.
Hardcore skill development is also one of the greatest social mobility hacks.

Consuming is only helpful insofar as it enables you to produce.

Pursue a domain you love, but simultaneously get so insanely technically skilled at math and coding that you can apply them to your domain of interest in an innovative way.
Deep domain expertise plus alien-level technical skills equals lots of interesting and rewarding work to do.

Learn the combination of:
(1) Domain expertise to identify an important problem and envision a solution,
(2) math and coding to build it,
(3) communication to deliver it.
Without (1) domain expertise you’ll choose an unimportant problem or your solution won't really solve the problem (because you don't really understand the problem).
Without (2) math and coding you'll be limited to whatever someone or something else (without domain expertise) can build for you.
Without (3) communication skills your solution won't be understood and adopted: You'll mistake lack of traction for lack of merit when it's really just a failure to articulate value.

You can make serious progress climbing pretty much any skill tree if you just put in 30 minutes of focused effort every day.
But it has to be fully focused, continually upping the level of challenge.
Work intensely enough that you come out of each session seriously winded.
Your brain feels like mush or your body feels like jell-o.

To get the equivalent of 30 minutes full-assed, you have to put in at least 2 hours half-assed.
If you put in 30 minutes half-assed, you get the equivalent of 7.5 minutes full-assed, which doesn’t move the needle fast enough.
What you expect to take 5+ years turns out to only take a single year or less if you train seriously, consistently, efficiently.
Don't get discouraged by how long it takes people who don't take their training seriously.

The most superior form of training is “deliberate practice”: mindful repetition on performance tasks just beyond the edge of one’s capabilities.

Strain can be unpleasant.
It’s taxing and it leaves you fatigued.
You may feel weak, untalented, and dumb.
You feel weak while exercising but you come back stronger.
You feel dumb while studying but you come back smarter.

Ability is NOT something to be “unlocked” by curiosity and interest (which seems easy).
It’s built by deliberate practice.
Curiosity and interest “grease the wheels” but they don't actually move the wheels.

Confidence needs hindsight.
If you feel confident, it’s not because the task in front of you seems easy
It’s because you’ve been in situations before where tasks felt challenging relative to your abilities but you’ve always managed to come out successful.

Grinding through concrete examples gives you intuition that you will not get if you jump directly to studying the most abstract ideas.
If you go directly to the most abstract ideas then you’re basically like a kid who reads a book of famous quotes about life and thinks they understand everything about life by way of those quotes.
The way you come to understand life is not by just reading quotes.
You have to actually accumulate lots of life experiences.
You might think you understand the quotes when you’re young, but after you accumulate more life experience, you realize that you really had only the most naive, surface-level understanding of the quotes back then, and you really had no idea what the hell you were talking about.

A company's balance sheet can tell an incredibly interesting story if you have visceral experience with success and failure in business.
But if you don't, then analyzing financials will make you feel like a robot checking whether numbers match semi-arbitrary conditions for being "good" or "bad".

If you’re pushing 25% of the time, then there would be a 4x multiplier by pushing 100% of the time.
4x speedup is the difference between a decade of work vs a couple years.
If you’re pushing 90% of the time, then the multiplier is down to 1.1x.
It’s basically max capitalization with a slight rounding error.
That last turn of the dial from 90% to 100% is not going to change the overall outcome – all it will do is create regret in other areas of your life.

Practice is supposed to challenge you, but how hard is too hard?
Focus less on feelings, and more on measurable progress.

Want to practice effectively? You absolutely must:
1) Have some concrete way of measuring your progress
2) Make sure that whatever you’re doing is actually increasing that progress
3) Make sure that the progress is increasing fast enough that you’ll reach your goal in a reasonable (but realistic) amount of time.

Get in this cycle:
* Put in the work in a favorable practice environment.
* Build up your ability.
* What used to be hard becomes easy.
* See the growth you've achieved.
* Imagine how much more growth is in your near future.
* Gain confidence in your present skills and future trajectory.
* Gain motivation to keep on working hard.

Benjamin Bloom discovered this in the 1980s while studying the training backgrounds of 120 world-class talented individuals across 6 talent domains (piano, sculpting, swimming, tennis, math, and neurology):
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STAGE 1: Fun and exciting playtime.
Students start to develop awareness and interest in the talent domain.
Teacher provides copious positive feedback and approval, and encourages students to explore whatever aspects of the talent domain they find most exciting.
Students are rewarded for effort rather than for achievement, and criticism is rare.
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STAGE 2: Intense and strenuous skill development.
Students are committed to increasing performance.
Teacher becomes or is replaced by a coach, who focuses on training exercises where the sole purpose is to improve performance.
Exercises are demanding, and coach provides constructive criticism to help the student perform the exercises properly.
Positive feedback is provided in response to achievement. Effort is assumed.
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STAGE 3: Developing individual style while pushing the boundaries of the field.
Students are proficient in the foundational skills.
They are so committed that they center their entire lives around the talent domain, no matter the sacrifice, and typically work with a world-class expert in the talent domain.
Expert helps the student identify and lean into their individual strengths so that they can excel beyond perceived human capabilities.
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However, there are several failure modes that one can run into when attempting to make the journey through these stages:
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FAILURE 1: The permastudent perpetually avoids the leap into creative production, opting instead to “expand sideways” and acquire skills that are not foundational for their talent domain.
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FAILURE 2: The wannabe jumps the gun on creative production before their foundational skills are in place. They build a portfolio of work that lacks substance and is made trivial by foundational knowledge. Not only is it cringe, but it also has high opportunity cost because all this time could be put to better use actually acquiring the foundational knowledge.
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FAILURE 3: The dilettante cuts their journey even shorter than the permastudent – they never even make it past playtime, they never commit to serious foundational skill development in anything. The dilettante spends all their time in the land of diminishing returns, engaging in perpetual playtime across a large number of talent domains.

If you’re not measuring performance and taking actions to improve it, then you’re not seriously training. You’re just playing around.

Day-to-day variety can arise from focusing single-mindedly on one big mission.

One of the best career hacks for a junior is to knock out your work so quickly and so well that you put pressure on your boss to come up with more work for you.

Consistently hardcore people achieve extraordinary outcomes through extraordinary actions.
These actions go beyond the ordinary and are often seen as crazy.
Framed as love, this is familiar: everyone knows that love makes people do crazy things.

Why extrinsic motivation matters:
People whose motivation is entirely intrinsic sometimes prioritize “fascinating distractions” over other things that would be more productive to their long-term happiness.
Intrinsic motivation gets you working on interesting things with a unique perspective.
Extrinsic motivation keeps you on the rails with your long-term goals and keeps you from falling victim to fascinating distractions.

For super-productivity, interleave a wide variety of productive work that you enjoy.
You get tired, bored, and unproductive if you’re moving along one dimension for too long.

Fluency in consuming information is not a proxy for actual learning.
You haven’t learned unless you’re able to consistently reproduce the information you consumed and use it to solve problems.
That comfortable fluency you feel while following along is arising from the fact that the surrounding context is already on your mind – you’re not made to pull it from long-term memory.
When you feel like you’re absorbing information while passively following along, what you perceive is information sitting in your working memory, not your long-term memory.
If you want to test whether information is in your long-term memory, you have to actively attempt to retrieve it when it's not already at the front of your mind
Switch over to active problem-solving immediately after consuming a minimum effective dose of information.
Reviews should feel as mentally taxing as initial learning.

In weightlifting, you need to increase the weight to the point where you struggle to lift it, but you are able to overcome the struggle.
That’s how you build muscle, and that’s also how you build long-term memory.
Spaced repetition = “wait”lifting.
Spaced repetition is so similar to weight training that you might as well call it wait training.
You’re lifting a memory off the floor of long-term memory and raising it up into working memory.
The fuzzier that memory, the harder it is to lift.
The wait creates the weight.
And just like successfully lifting heavy weight strengthens muscles, successfully recalling a fuzzy memory (lengthy wait) strengthens memory.

The typical approach to education involves maximizing other things like fun and entertainment while, as a secondary concern, meeting some low bar for shallowly learning some surface-level basic skills.

Every time you study, imagine the Grim Reaper is going to show up at the end of your session to quiz you on what you covered, and if there’s any question you can’t answer correctly, you die.
Whatever study techniques you’d use in that situation, you better be using them already.

Learning is memory.
Understanding amounts to memory that is well-connected and deeply ingrained.
If someone is "just memorizing" as opposed to "deeply understanding," it really means they haven’t stored enough information in memory.

The most effective way to learn is to use memory-supporting training techniques.
It’s easy to get confused, thinking: "Truly understanding something is different from just memorizing it, so learning doesn’t require memory-focused techniques like retrieval practice, spaced review, and interleaving (mixed practice). Those are about memorization, not true understanding."
If that’s what you think, then you'll likely shirk the hard work required to build memory,