One time as a kid, a friend lent me her glasses (I never needed glasses, but I always liked them) and I went to climb a tree. In the tree, looking down, the glasses made it seem like I was much closer to the ground than I was.

So I jumped.

It was extremely stupid. There was a point during the fall when I felt like I should've reached the ground already, but I hadn't. In the end I was fine, the glasses were fine, and my friend thought it was funny. But wow, that could've gone disasterously wrong.