A natural log
He found the apple was a surprisingly down-to-Earth kinda guy.
Roll a penny down a hill.
He was looking for Pooh. - *My little brother told me this one hit me with a little bit of nostalgia.*
By leaving a plunger in the toilet
A natural log.
They would have discovered Penicil(e )
Because its natural log is 1. I'll show myself out now.