HELP!!!!

I think overall Cory and I are pretty good parents. However, we are in need of advice, help, something!!! I am not aware of this stage (at least, I hope that is what it is) and will take any suggestions on how to make it end.

Our child, the perfect, sweet, little angel he is is going nuts. For the last couple of nights, we have found him BANGING HIS HEAD ON THE WALLS. Out of nowhere, he will walk up to the wall, put both hands on, and bang. At first, I couldn't believe it but quickly came to my senses when he banged his head on the GLASS OVEN DOOR...twice...really hard!!!! Lord - I thought he was going to break the glass. He thinks it is funny...just looks back and laughs. It is very random also. He will be very calmly sitting on the floor reading a book or playing then will get up and go bang his head. We kept telling him to stop cause he was going to get a big ouchie but that doesn't seem to work. I originally thought - let him keep doing it and he will eventually do it hard enough he won't do it anymore. But them, I don't want him to hurt himself, tear up the walls, or break my oven :)

IS THIS NORMAL???????