When you were young, did random things give you an erection/turn you on?

Here's what I think happen(s/ed): for some reason us men get erections for no reason sometimes, right? This is called a NRB: no reason *****, I think by a freak coincidence,like, I don't know, say... 3 or 4 times this happened (because it's bound to happen at some time or another) you realized hey when I pass by something involving smoke I get an erection (it doesn't matter if it was a concious or subconcious observation) then, the placebo effect takes effect (the placebo effect is when something happens because you think it will happen, in lamen's) so, now because you think you'll get an erection, you do! : )