I did. I read some of Twain in high school but didn't really "get it", in hindsight. Then as I grew older and began reading many of Twain's endless quotes it made me want to go read more of his works, and I'm glad I did.
I think high school readings are quite pointless in general, because most kids either aren't mentally developed enough, or aren't going to have the focus, to actually "get" what's being said - at least not beyond the point of cramming enough stuff down to be able to puke it back up on a test/report.
That was certainly the case for me and I think this is extremely common given there are plenty of people that think Huck Finn is a racist book, when the entire underlying message is a never-ending mockery of racism.
Maybe the point of high school readings is just to give you some books that will be relatable when you’re finally an adult.
> because most kids either aren't mentally developed
I've gone back and read so many books I was supposed to have read in HS and college. I don't think at the time I had the life experience to fully grasp many of the message(s). It's one thing for a teacher or guide to explain in abstract the underlying messages, it's another to have dealt with them in your own life and see yourself in the characters [1].
[1] I always read like I'm one or more of the characters and not simply an observer.