My 1 year old has suddenly become unmanageable?

you hit it on the nose! terrible twos already! I don't know why they call it terrible twos my daughters pediatrician told me this type of stage can last till they are 6 years old or better (and more problematic actons will come believe me!) right now you just have to grin and bear it. use discipline and stick to it. and don't let him get his way all the time or he will stay like that