Don't be depressed. It's possible some fellers exaggerate a little on the internets. :wink:
exactly what i wanted to say!
i'm really not accusing anyone of lying but 99% say like "anytime i want, i just have to think a little and my dick gets rock hard in a second", then you look at their gallery and half the case you only see semi-hard pictures, just rarely a proper erection. and this probably WITH the help of their hands...
so don't be depressed at all!
its true that for example when i was a teenager, i had erections for no reason, mainly during school. i was sitting there listening to the teacher or maybe looking at the girls in class, whatever, and suddeny i noticed i have to hide my erection... again

than it stopped at the age of 15.
BUT even this doesn't fit in the "erection on command" category!
personally, i think such thing doesn't exist. a man with a lot of practice+work may control a nice extent of his brain (and through that his body), but having erections on command.... no freaking way (in my opinion)!
now i'm 24 (so i wouldn't call myself "old") but i definitely need some kind of stimulation to get hard. i can reach a semi-hard status by sexual thoughts, but thoughts are not enough to get fully hard.
and i think thats totally normal. only porn tries to tell us that a real man walks around with a hard-on all the time. what a bullsh*t.
if you look at it closely, you can see that in 99% of the adult films they simply "skip" the part when the guy is still soft and reaches an erection. instead its like this: in the one scene they are kissing on the couch, a quick cut and the girl has already a rock hard cock in her mouth.... well HOW DID THAT HAPPEN??
of course noone really asks and the only thing that remains in the head of every boy and men that you should be ashamed if you don't get 100% erect just by thinking of sex. because "normal" guys can produce rock-hard erections on command, anytime they want....... yeah, sure.
sorry if its too corny, but i see this as one of the greatest damages that porn (+media) does to our soceity because through this they cause huge insecurities in most (young) men and no wonder that erectyle disfunction is no longer an issue for men above 40 but affects a growing number of young folks as well!