When I was a kid I thought it was "Maxwell Jump" instead of "ah, might as well jump" from Van Halen's song "Jump" on their album 1984.
Mattchoo
A childhood belief about misheard lyrics

others believed things like this
- My little brother was afraid of toliets cuz he thought monkeys would jump out of his butt.— ~~~ Crazy Bro ~~~
- I ues to believe that if I broke th TV the people would jump out and try to catch me.— Lazyj (K)
- I used to believe that if you jump in a toilet, they lead you to another dimension.— beep.
- -nursery rhymes-
i used to believe that cows could jump over the moon when I was a kid.— Aloysius - I used to believe that if you stepped on the cracks of the pavement, a bear would jump up and eat you.— Nina
- When I was little my dad told me that monsters jump out from spotlights and I belived it...— Cassie