" We have found that the sexual life of man, unlike that of most of the animals nearly related to him, does not make a steady advance from birth to maturity, but that, after an early efflorescence up till the fifth year, it undergoes a very decided interruption; and that it then starts on its course once more at puberty, taking up again the beginnings broken off in early childhood. This has led us to suppose that something momentous must have occurred in the vicissitudes of the human species which has left behind this interruption in the sexual development of the individual as a historical precipitate. This factor owes its pathogenic significance to the fact that the majority of the instinctual demands of this infantile sexuality are treated by the ego as dangers and fended off as such, so that the later sexual impulses of puberty, which in the natural course of things would be ego-syntonic, run the risk of succumbing to the attraction of their infantile prototypes and following them into repression. "
― Sigmund Freud , Inhibitions, Symptoms and Anxiety