You don’t have to be an Einstein … but it helps.

This iconic photograph was taken on Albert Einstein’s 72nd birthday, March 14th 1951. Apparently the photographer was trying to persuade him to smile for the camera, but having smiled for photographers many times on that day, Einstein stuck his tongue out instead. The original photograph (taken by Arthur Sasse) sold at auction in 2009 for $74,324. Had he licked it as well then it would have gone for even more … relatively speaking.