When does a hobby turn "nerdy"?

There are things that we do that we think are cool and manly, then it turns on us. It started with motorcycles and it turned into artistic expression and understanding. We have a relationship with art and poetry that we do not think past the songs we're singing. Dr. Jordan B, Peterson says "We don't have ideas, ideas have us." How do we cope with that and What makes a passionate hobby into obsessive nerd like behavior?