Two year old is really wearing me down.

Since his 2nd birthday to the day, he went from this really sweet curious boy to this very violent, disruptive, obstinate kid.He doesn't care about timeouts, he asks for them. We don't spank or hit, so I don't even know where he learned the behavior from. He hits all the time. He is brutal to other children. he just attacks kids for no reason.Prior to his second birthday he was very caring, he shared everything. If a kid at a playground stole a toy from his hands, he didn't even mind, now he would tackle the kid take the toy back and beat him with it. It's so bizarre.We are a pretty calm house, not completely void of arguments, but it's minimal. He gets tons of attention and love. A healthy diet. His sleep is terrible, for us. He sleeps from 7:30pm to ??? If we are lucky he sleeps until 6:30 with one wakeup around 2:30 for half hour to an hour or more. But more often than not he is up around 4:30 or 5:30 plus the wake up and it's tough.He is intelligent, everyone thinks their kid is smart. He is genuinely intelligent, nevermind all the memorization of abcs and counting to 20. His problem solving is absurd. We dont tell him he is smart, but its obvious. Everyone knows it. I have nothing but his cousins to compare him to. But everyone says it, constantly.We have always talked to him and treated him like a person and not a child. We explain everything to him in adult language. Some parents have mentioned they think it's weird that we talk to him so matter of fact. We didn't plan to do this, it just happened organically. It may be the problem? I don't know. I don't know what we could do differently.His doctor doesn't seem to think anything is abnormal. He is healthy and it's just "terrible twos". Well they are much more terrible than we expected. Just ranting I guess. Hoping for some advice. via /r/Parenting http://ift.tt/2glQgx0