To what extent is the guys always have on the brain thing true?

for some reason, I never fully understood that, cause guys don't always have on their minds, although when they are teenagers and just starting puberty, yeah they do have on their minds like 50% of the time, but after the teenage years, I think a guy probably only thinks about 35% of the time, it's not like every girl a guy sees, he want's to have with. doctors and ministers might think "hhm?" when they see a hot girl, but they wouldn't do it that much and if they did , when they look at the girl they don't automatically switch into ual mode. When a guy see's their friend's pretty daughters, they aren't gonna automatically think," man, I wanna get that" I think their are about 25% of guys who are auctually horny 80% percent of time while the other 75% really aren't, and it's just a stereotype in this world