Have you ever discovered anything completely by accident?

Have you ever discovered anything completely by accident?
When I was a teenager I told my boyfriend that his ex called me and told me they had sex. I was joking just to see what he would say. He started trippin out and told me it was only one time blah blah blah! I was devastated!
I discovered something embarassing about sex complately by accident. Y'know, I don't care if it IS Health class, there are just some things you do not want to know!!