Hitting the Wall

My 4-year-old came home from preschool today with a nice little 'bonk' on his nose. I asked what happened and he said "I had a fight with the wall but I think the wall mighta won." so I said "Were you not looking where you were going?" and he says "I was lookin' really good but I was running super fast and I just hit it. Then I had to stop." Ah. I know exactly what you mean little man.