I got my first guitar when I was 12
Started playing Bullet for my Valentine songs immediately.
Grew into A Day to Remember and those two combined to begin with really set me up for my future as far as technique, rhythm, hand-to-hand coordination, etc.
Around 2006ish, I was shown Bat Country and I was hooked to A7X ever since. This Synyster Gates guy really opened up a new world to me with the solos this dude plays and I picked up lead guitar immediately.
It wasn't until I was 18/19 when I really delved into music theory as a whole and my eyesight broadened within the musical universe.