Young infants have little control over anything. They can’t move their bodies toward things they want or away from things that are unpleasant. They don’t have very good control over their hands, so that grasping and manipulating objects is not easy. They get poked, prodded, picked up, and put down at unpredictable and inexplicable times. The world is just a set of things that happen to them, leaving them completely at the mercy of others. It is perhaps for just this reason that the occasional bits of evidence that they can control certain things are so salient and so exciting.
