I would hope it's not about becoming an awesome shredder. That stuff is awful.
You can learn/hear a lot of theory w/o having to be told it's so. For instance, it doesn't take a degree to realize a I, IV, V progression "sounds" good. You could also probably figure out that notes in a major, minor, or pentatonic scale sound good together. These are simple examples, but examples nonetheless.
When it comes down to it, theory is merely putting names to things that are supposed to sound good and you don't have to go to school to figure this stuff out. It might be helpful & you'll learn the names for a lot of the stuff you already know, but really... One could "hear" theory without really learning anything. A 5 year old Mozart, for instance... For you classical folks. The rock & roll folks already know. Haha.