Wow I thought I was cynical. Have you considered doing something new? Learning a new framework or language often gives me a fresh perspective on past projects.
Dude, when most programmers hit 25 they have already learned dozens of frameworks, know how to build compilers, machine learning, etc. The problem is after a certain age, all the cool/novel stuff no longer is, and it becomes boring as hell and your back to building CRUD Apps and your still got most of your career ahead of you.
What 25 year old developers hasn't learned frameworks like django, rails, Java EE, iOS, node.js etc. I know fair few frameworks, some more than others.
The majority of university courses teach you compilers(Parsing, Multi-pass optimisation, machine code output) and ML. I've built a fair few compilers in spare time, and I'm in no way special within my peers. Sure the stuff you learn probably isn't leading edge in terms of research, but unless you take a second job reading research papers, it isn't going to happen for most software developers.
The most enjoyable part of job is probably introducing better software processes, but once it is set up well, I get bored again.
25 year old here, I agree. I only know enough of the frameworks I've learned to solve the problems I've come across. As far as compilers and ML... yeah, I know a little bit of that stuff, but it's far from common for people in my age range to be good at it.
I try and learn a new framework and a new language a few times a year.
They never solve the actual fundamental problem of computing - we still trust computers less than a four year old when it comes to understanding context and meaning in language.