The world is an uncertain place. Nothing is ever definite. The only constant is change. If we adults are sometimes threatened, scared and confused, what more a child. A child not fully sure of his surroundings. For a child to develop fully, they must and will push boundaries. They need this to grow and evolve. But this is not intentional or with malice. This is just part of their way of going about in the world. Of teaching the adults in their lives.
They are testing their limitations. If they are to be the adults they are meant to be, they have to ask a lot of questions. It might take a few times of answering before they are able to process your answer. Their minds work very hard to connect the why’s and how’s of things.
At the very onset a child is a blank slate. We do not know what he likes, how he prefers things. Only by patiently listening and plenty of guesswork do we determine what they want to say. This gets easier in time as they learn to speak. They will let you know of their opinion on anything. Loudly and in between jumping. The age of development is also the age of discovery. Discovering what these children like. Their personalities, idiosyncrasies, it is all developing. 
On more than one occasion, we need to practice patience. If they want to play alone sometimes and push other children away. This may be because they are protecting their sensory from overloading. Their processes are different from other children. Giving them the chance to experience other things can benefit them greatly. Sports, gardening, dancing, history and all these incursion and excursions for them to experience. Sometimes they will have interest for only one activity. Sometimes seeing other children enjoy the other things will entice them to try it out. His social awareness and interaction builds as he interacts with others.
The way he behaves and progress is the child teaching the adults around patience and to adjust for a new person. The people around giving him new opportunities and things to try out is the adult teaching the child there is a place for him in the world.