When my brother was about 9 years old he awoke about 9:00pm walked into the kitchen area where there was a small garbage pail, peed in the pail, and went back to bed....all without remembering,......all while my parents looked on in amazement. He has not lived that down to this day.
My brother has done much worse — as a grown man.
I did the same thing as a kid only peed in a closet, thought I was in the bath room.