Lately my 3 1/2 year old has been getting really angry and frustrated over little things. If he's doing a puzzle and can't find the right piece, or spills a drink, or just whatever, he gets so mad. Sometimes if I tell him he can't do something, or if he doesn't like something that I'm doing, he'll hit a chair or table, throw things, or try to hit me. I've told him that it's okay to feel frustrated and angry, but it's not okay to hit people or objects, and that if he's having a hard time with something, he can ask for help or try again instead of getting angry. It doesn't really help, though, and I hate it when he goes all aggro about little stuff. Any advice?