Seeing faces

Throughout history, people have reported seeing the patterns of the moon's craters and landscapes forming things humans recognise, such as rabbits, women or a boy.

There's a technical term for this "pareidolia" - where the mind sees a familiar pattern where none exists. The human brain is actually hard wired to try to find meaningful images in any random pattern.

Throughout the whole of mankind's existence, many have reported seeing "the man in the moon", a face which can be traced from these surface features forming eyes, a nose and a mouth. Some remember sometimes having to stare for a while before seeing it, whereas others saw it right away. When asked to check today, or at least at the next full moon, they are surprised to find the one they remember isn't there at all. Was this only something which appeared in childhood?

Seas

There was a long period in human history when people thought there were seas on the moon. We now know they are hardened lava plains, so in a sense they were at one point seas, though not of the kind you'd like to spend any time near. They flowed with a different kind of material than the surface, so when they did harden they were of a different color, hence the patterns we can see from the Earth. 

A cultural thing

The idea of a figure in the moon is ancient, and many cultures / religions have given rise to them. Sometimes it's an animal such as a rabbit, others have said they saw a pair of hands.

There are reports of the moon changing it's appearance in other ways too: