"A nocturnal emission is the body's way of relieving sexual tension, which becomes particularly high at the adolescent age (Mas1and et a1., 1980). These emissions characteristically begin when a boy is 11 to 16 years of age (Mas1and et al., 1980). Thus, nocturnal emissions are primarily seen as a phenomenon of single males in their teens and early twenties. A high percentage of all males do experience nocturnal emissions at some time in their lives. Ultimately, about 83% of all males have wet dreams (Kinsey et al., 1948). Katchdourian et al. (1979) state that practically all males report having had erotic dreams to orgasm at least once. McCary (1973) reports that almost all men have erotic dreams and 85% of them have had dreams that culminated in orgasm. Kinsey et al. (1948) recorded that some men experience orgasm practically every time they awaken from sleep, even though this may be two or three times in a single night. Thus, orgasm as the product of nocturnal dreams is well known in the male."
January 1, 1970
https://en.wikiquote.org/wiki/Nocturnal_emission