I spent a lot of time over the last few weeks studying for the class I was taking this semester: Advanced Operating Systems. The class, albeit fascinating, was extremely challenging.
The good news is that I learned a ton. It's incredible how many things directly related to the way operating systems work I was able to apply to several of the projects I have going on right now: from caching strategies, to load balancing, threads, and barriers.
This experience has been incredibly humbling. Even things I thought I knew I've been able to look from a totally different perspective. The amount of stuff I've learn in such a short period of time is amazing.
If you have the opportunity of going back to school, please do it. You might have to pay for it, but it's hard to justify not doing it from the knowledge perspective.