Is this just a stage?

I don't understand the destructive aggressive nature of boys. Jeriah has this drive to randomly and unexpectedly run into people and ram them with his head or simply knock them over, namely me and his brother. We have talked about it, demonstrated it, taught it in every way I know how, that it's not OK to run into people and knock them over. I'm fed up! Two minutes after we talked about it AGAIN today, Jeriah shoulder butted Lukas and knocked him into the corner of the door, which rebounded and hit the poor kid a second time.

Throwing, hitting, breaking, taking things apart, tackling, arguing, yelling, chopping, kicking, and more... What's the deal? There's very little softness, understanding, caring. There are days that I feel I'm just a constant referee, stopping disasters before they happen, enforcing rules, and generally keeping the destructiveness in check through a lot of arguing and timeouts. I sometimes find it difficult to play with Jeriah by wrestling or tickling because I'm usually the one that gets hurt and has to stop. And it doesn't seem to matter how many energy expelling activities I have planned for the day. His energy level doesn't seem to waver. He just gets more hyper and more belligerent.

Are all four year old boys this way? I think I need a padded room with a lock on the outside so he can just go in there and throw himself around until he's exhausted.

Who said that two year olds were terrible? ;)