Tom has a short answer when the subject turns to learning: “Seat time is the yardstick.”
It means the hours you spend actually doing something matter more than the hours you spend talking about it.
Software makes that lesson clear. You can watch a lesson about building an app. You can read about it. But the real education begins when the app doesn't behave, the compiler complains, or the button you need seems to have vanished.
The useful kind of mistake
Consider the Tack Mobile App Store adventure. One wrong action in Xcode erased a project target. The code survived, and a backup helped put the target back. The answer to the original problem turned out to be a tiny minus button in another editor.
Not fun in the moment. Very memorable afterward.
The next time Tom meets a stubborn project setting, he will be better prepared. That is seat time paying interest.
Build, use, discover, improve, ship
Tom's software gets tested in his own work. If a tool wastes time, he notices. If an interaction feels awkward, he lives with it until it gets fixed. A release is not an end point. It is a tool entering real life.
Sometimes the right answer is to add a feature. Sometimes it is to keep a simple app simple. Both choices require judgment.
No finish line
The more you build, the more you see. Problems get smaller. New ideas get bigger. You begin to recognize which battles are worth having and which ones are just expensive beaver dams.
That is why the yardstick matters. The work changes you while you do it.