Theoretical and CS fundamentals has never been an issue for me (no degree), because I find them interesting. Probably more interesting than most of my coworkers. I think you'll find this is the case for many people who end up in this industry out of passion rather than educational path. A year unemployed during the .com crash gave me lots of time to work on open source hobby projects, where I wrote my own virtual machine, compiler, etc. That was fun. Wish I could afford to do that again.

Honestly, what I find I'm missing is mostly class status and a piece of paper.