What does it mean if you have a dream about a boy you like?

It means you think of him too much, dreams reflect our inner desires/fears/hopes, they mirror our unconsciousness, even when we have a weird dream, it's something from our inside but it's blurred, we write it down and link it to people and things around us and it starts to make sense :)

Using psychoanalysis, you dreamed about him because you desire his presence

It simply means that you think of him a lot .