I want to knock a child down
Why do you want to knock a child down?
I am in the mood to knock somebody down
If you knock down a child on purpose, then you could be considered a child abuser. You should never put your hands on an innocent child or you could wind up arrested and in jail.
I don't like children, they annoy me and are disgusting.
Not everyone has to like children, but it is wrong to hurt them. You can get into a lot of trouble for doing something like this. It is better to just ignore them and take your frustrations out on something else.