What was your f*ck around and find out moment?

for me when I was in boarding school. My room (it was a big hall type) was on 1st floor and this one night I saw a senior sitting in the lawn right below the window, so I started f*cking with him, kept dropping sticks, small stones and sand on him and each time he got angrier but didn't react until he did. He got up and and went towards stairs and then I panicked. I ran across the hall towards my bed and tripped on a wall corner (it was really dark and I couldn't see anything). The tiles pierced into my chest and it started bleeding. I didn't feel a thing until I felt the blood liquid wetting my tshirt 😹. Could've been worse injury but wasn't and for the better. No one has ever known about that.