Hey Pandas, What's The Thing You've Considered 'Normal' While Growing Up, Only To Find Out It's Actually Weird?

When I was younger (about 5) I would bite my toes because I thought it tasted good. When I went to my first day of preschool, I took off my shoes and started to do this. Obviously everyone was confused there and grossed out, but I learned not to do that because it was (obviously) disgusting.