It is an interesting fact about sensations that one naturally has them, and that very little or no learning is involved in the abilities of seeing, hearing, smelling, feeling etc., though there seems to be quite a lot of fine-tuning of these abilities in one's early years (and sometimes also in one's later years when acquiring special skills).

A related interesting fact about sensations is that people usually easily come to agree about them (it usually takes little discussion to decide whether or not there is a hippopotamus in the room, nor whether the hippopotamus in the zoo is really yellow or not), and normally attribute the capacity of having them to each other - even though (apart from ESP) no person can have the experiences of other persons. (See: Other minds and Qualia).

In any case, the capacity for having sensations of various definite kinds, related to sense-organs, is one of the foundations of empirical knowledge and the possibilities of human agreement and cooperation.