I remember lots of my classmates wet their knickers or pants at one time or another in nursery school (that's preschool to the Americans ... age 4) or the first year infants (age 4 / 5) ... but I NEVER DID ... and I was EVER so proud of that achievement ?
At the beginning of second year infants, a girl in my class wet her knickers twice ... two weeks apart. And I remember thinking "How can anyone be so dumb as to have an accident in the SECOND YEAR???"
And then finally, in the summer term of my second year at school, when I was nearly 7 ... wouldn't you just know it? Little Miss Perfect finally waited too long one day and wet her knickers at school!!!!!