Interesting topic. I'll share mine though I don't think it's held any influence over my pee fetish (see my first post)
My folks say I was pretty good until my brother was born, then I started having accidents for attention, though I don't really remember this at all.
I wet myself one time in grade 2 or 3 as I'd been holding all day because I was scared I was going to poo at the same time (which had happened at home and I never pooed at school if I could avoid it)