There's a lot of stress to being a dad. We've taken a good look at the world now and all we see is the danger you kids are in. It's hard for us to think of all the bad things that may happen.
Then there's the fact that kids just don't listen to logic. We try to explain things logically only to see our logic get completely short circuited. :P
Then there's the fact that kids leave the lid off the peanut butter no matter how many times you tell them not to. And when we say no, kids ask the exact same question that we just said no to, only in 50 different ways, hoping we change our mind.
After all of this we're just frustrated and our tops pop. :)
Soooooooooo . . . it's all the kid's fault. *nods* That's why.