Don't you think there could be some porn influence though? Less the actual visual element, but perhaps the M element. For instance, for years I've been watching porn and edging - you know, watch a scene, maybe jack off a bit and then chill out and watch another, building to a climax an hour later, intermittently M'ing and letting my erection go from full strength to half strength with the breaks and so on.. Surely that kind of routine may have wired in some faulty sexual ideas about not needing a solid erection 100% of the time. I'd be interested to know if the OP often PMO'ed like I did, in that you edged over long periods letting your erection reside and reappear when you found a scene / image that turned you on?