I talk about the single most important thing you can do to hone your skills and get a job in the game industry: make a demo.
Cain has mentioned this in many other videos, but he still asked after a year how to get a job in the industry. His answer is always the same, make a demo. Self taught, going to school, how do you learn best how to do X? If the answer isn't money, make a demo. Will wrap all of this together in a neat little story.
Cain is the last of five kids, the first 3 are all 2 years apart then there is a 6 year gap and then two more kids two years apart. When they were young, they used to try and figure out which one is mom's favorite. Couldn't figure it out, mom loved all of them equally, but they were all very different kids. Athlete kid, cheerleader kid, architect kid, game kid (Cain.) Mom loved them all and loved encouraging their hobbies, but they would sit around and debate who was the favorite. Kid 1 would argue as the first kid they got all the love and best jeans. Kid 2 would question Kid 1's taste in jeans. Kid 3 would say they are the neglected middle child and refuse to enter the conversation. Kid 4 would wait for Cain to say he was the most loved because he was the one they achieved perfection and decided to stop with, and respond that you don't know you've reached the top of the mountain until you start down the other side. Cain disagrees and thinks they did achieve perfection with him, but that has a lot of applicability to what Cain is talking about, you have to actually make things and use your skills to find where your strengths are and what your maximum is. Cain's video on learning from failure was important because his failures let him hone in on what he is good. It wasn't clear if he was good at writing after Fallout's intro, Cain would only realize his difficulties with long form writing on ToEE. Temple of Elemental Evil isn't winning any writing awards like Outer Worlds did, and he didn't write that.
On the idea of going to school vs. being self taught, regardless of what you do, you should make a demo. It's ok to skip school if you are motivated enough to make the foundation of knowledge you can build your skills on. You also have to be good at self evaluation and see your flaws. If you think everything you do is great, either you are a genius or missing something. School is good for evaluation. Have to learn how to learn, and school can help with that by putting you in a conducive environment. Maybe you had a bad school environment, than self teaching is good. What Cain is getting at, you have got to learn some skills and then apply them. Have to learn by doing, have to actually do something, can't just think about it or read about it. When you do it, you can see how hard it is, what you are good at or bad at. Making a demo is a good solution for ideas, wanting to get in the industry, learn a engine or language.
People tell Cain they worry about job interviews, lots of tough questions to answer. Making a demo makes those questions a lot easier to answer. if someone asks you what language or engine you prefer, you can point to your experience making those demos and what you learned from that. A very common interview question is the most difficult feature you implemented. You can talk about that if you made a demo, with a real example. Maybe you wanted your demo to have dynamic lighting, and the engine implemented it oddly. Good odds someone in your interview had that same kind of experience.
You can try to get better at some of the things you are bad at, and for some of them you will and then can put them in the bucket of things you are good at. Some things you will never get good at, and that is fine, put it in the bucket of things you are bad at. You can still talk about it. Cain knows he is the right guy for short form lore text that needs to be funny, not the guy for long form dialogue between two characters. Cain knows that, and can point to good and bad examples.
TL;DR : Making a demo and actually using your skills, you will learn where your mountaintop is, what your strength is. Having a demo you can show people more than anything will help in interviews and getting into the industry.