I'm just starting to learn some music theory which was totally absent in my guitar playing. Been playing for ten years.

I didn't know and still don't know in what key I play when I do a solo. I just let it go. Most of the time I get something ok, I'm not the best soloist here but not knowing theory never stopped me from creating.

I just know when it sounds bad and when it's sounds good.

So I agree with Lalimacefolle but I must say a little theory the first year I played would have help me get where I wanted faster.