For me personally, the most difficult thing in my life to not take myself and life too seriously. Granted, I had reasons for it, but that still doesn't change the fact, that once I learned to laugh at myself, I felt insane freedom.
I mean, sure, at the age of 15 I was correcting grammar mistakes and wrong formulations in the contracts my father was writing or a year later I had to play hookie on one Friday, because we were traveling to buy a truck and I had to come along as the interpreter, or, for some reasons, I was familiar with formal etiquette and actually had moments, when I liked being all formal and polite [ don't ask me about that one, never figured out, why I have tendencies to be all stuck up at times ] or since my younger brother was into some shenaningans, that could land him in serious trouble, I was reading and able to comprehend and interpret criminal law …
And then there was this other thing: I always viewed other people as my equals. I didn't realize that I'm actually a lot smarter, than most of them [ well, even if I had, it probably wouldn't really change anything, I still view people as my equals, most of the time ] and I remember feeling very surprised, when people didn't know what I knew or had the skills I viewed as mundane and common [ like being fluent in a foreign language and using it grammatically correctly. BTW, English used to be my 3rd language for a long time ^_^; ].
If you are smarter than other people, it's good to realize it. Not because you are supposed to think less of them or feel superior. It's to avoid stupid misunderstandings, when you think, that you are saying something perfectly simple and clear and the other party has trouble just following, what you are saying, forget understanding. Because then the other party feels like you are mocking them and posing as superior. This one is very tough to crack and up until today I have to approach on a case-by-case basis. Adjust the way I speak, the words I use and how I present them. This one is not easy nor simple… but if you are in a similar position, and I suspect, that you are, it's something that you should keep in mind. It might make the interaction with people easier.