DMing has helped practice a lot of business skills...communication, organization, running a meeting. Making pretty documents in google docs :P

• I’ve learned plenty of words.
• I’ve learned to describe spaces and objects better.
• I’ve learned how to have conversations about expectations in a friend group.
• I’ve learned that some things need hard prep. Others can be improvised.

Some people just aren't a good fit. That doesn't mean they're a bad person, nor you're a bad person, but sometimes you just don't get on with someone in a particular context and that's okay. You can still be friends or do other things together. You don't have to do everything together to be friends.

It's okay to let people have fun even if it seems stupid to you, or they'd have more fun doing something else. So long as they're not hurting anyone, let it be. It's tempting to be like "you know, there's a whole game series about playing modern day vampires doing politics while holding onto their fading humanity" when some folks are doing that in D&D 5e, but it's almost certainly not worth it. Many people don't care about what you care about.

People learn in different ways. Some people really struggle with things that seem easy to you. That person who asks every week "what do I roll to attack?" or "Can I roll my armor against their sneak attack?" probably isn't doing it to be annoying. They're probably trying their best, even if their best is pretty bad by objective measurements like "getting the rules right'. Don't be a jerk about it. You can gently ask them about what they think would help them keep the rules straight (one player liked little notecards, another player benefited from watching games on youtube), but you can't just make someone learn.

I've learned that I'm apparently pretty decent at ciris management and completely awful at non-crisis managament.

As a DM, thinking on your toes has been invaluable. The ability to come up with ideas, explanations, and more on the fly has helped a lot at work in meetings when unexpected things come up.

Reading books in English

Compromise and communicating my boundaries! If you want the game to be fun for everyone, yourself included, you need to learn when to go with the flow and when to stand your ground on something, after all.