Sexuality is closely related to family relationships and morality, but it is separate. Humans have the wonderful ability to fuck at will. We are not constrained by natural cycles like other animals, but we are not taking advantage of this boon to our species. Instead, we think of sex as something which must be concealed like defecation and urination. Sexuality includes the virtuous, normal, and abhorrent morality of sexual practices, as well as the responsibilities of procreation.
Education is the secondary agent of the enculturation process.
It is important for the good of the individual as well as the good of the groups abstract reality. The individual is rewarded by not having to start from scratch. They are able to learn the knowledge gained from their cultures struggle to survive, while the groups abstract reality gains another advocate. Education is not necessarily formal, it can be any pedagogy from an uncle teaching hunting skills to a professor teaching calculus to the tacit behaviors learned from observation. Knowledge has evolved from our cluelessness.