Why am I the only one I know that have to frequent the ER with my child as much as I do?

People say that between the ages of 7 and 10 boys will give you the most trouble and for girls it's 13 to 17. I believe the whole heartedly. Jayden is 7 and for the last 6 months or so he has challenged almost every word that comes out of our mouth and seems to be determined to find out just how much he can get away with. He is so hard headed! Friday Night, Jayden had friends over to spend the night and they wanted to play with the puppy inside the house, I told them the only way he could come in is if he had bath. They agreed to give Zipper a bath, but needless to say I found myself right in the middle of giving the puppy a bath because they could not handle him. After I got him all dried off, I told Jayden to go to the kitchen and get the new collar I had purchased for him and bring it to me. Much to my dismay, he returned minutes later with a bloody hand. He had taken a kitchen knife and tried to cut the tag off the collar but missed the collar and cut a giant gash in his hand. As many times as he had been threatened within inches of his life if he touched a knife without our permission. What possessed him? After talking to a friend who's a nurse I was advised to take him to the ER. I was having myself a good little pity party, so I called my sister on the way and said "Why am I the only one I know that have to frequent the ER with my child as much as I do?" She really got a kick out of that, but not I. This child is about to put me over the edge. These next couple years are going to be a battle of the wills. I can see.