Without theory you can't truly excite yourself while playing. Try, just for once, to shut off that little singing voice in your head that hums out all your melodies just before you play them. Instead, just work your way up to a spot on the guitar and start insta-riffing.
If you are constantly playing what you hear within your mind---as in, you hear the entire phrase in your mind and then play it--your playing has a high chance of growing stale. This is just because most people have similar melodic sense, even non-musicians. And the common answer to this is 'well i can just think hard of a different this...that...' Yes, you could, but then you'd be different just for the sake of being different---blaise'.
My truest belief is that to be a perfect, unique, awesome guitar player---it cannot be just about your ear. Just as your theory skills can fail you, so can your aurals. Try to just express yourself. This involves using your ears to get a general idea of the sound your are going for---no specific notes, just the mood. Then it involves using your theory to illuminate the fretboard and show you where to go, and then it is on you to go there. Your theory guarentees that no matter what you play, it will fall into that soundscape your ears have drawn. Half the time, you play melodies that resolve with beauty and the other half, they will sound 'original' and creative.
Most of the time, players that are world-class have this almost perfect ration in their playing: 50-50. Half of what they play you can predict and follow, and half of it is 'new' and exciting.
Theory can save you from your ear, just like your ear can save you from all the pedantic theory. And your fingers save you from both, when need be. Just let them fly every now and again---fall down the stairs and try to land on your feet.
It's more about approaching the guitar in different ways than it is about becoming a boring academic.
Back In Black isn't a song. It's a divine call that gets channeled through five righteous dudes every thousand years or so. That's why dragons and sea monsters don't exist anymore.