Late poster. Sorry.
I just had to chuckle. Thank you for sharing.

About 20 years ago, when my youngest boy was 2, we were were hiking up to Timpanogos caves. He was toilet trained but we put a diaper on him for the ‘long walk’. Well he had to go half way up. We told him to just pee in the diaper. “No!!! I can’t!!!!”
Ok, so we let him go on the ground. From that day to today he has in no way forgot “never pee uphill or upwind.”

-Barry