Under construction

Y do old people linger around construction sites?
To be precise, I should say "old men" and not "old people". I seldom see old women in this kind of situation.
But it's a sure thing. Whether a hole is being open, or a stadium being built, you'll find old men just staring at it. And it's not for a couple of minutes... No, some stay there for hours! Just watching... I'd really like to understand  this phenomenon...
Maybe it's related with a return to childhood... Since we Portuguese call old-age "a segunda infância", and given that lots of kids (boys) are hugely fascinated by construction toys (cranes, bulldozers, etc.), perhaps the passage of time brings that past allure to the surface of an aged mind.
Or maybe there's just lots of old men with nothing to do but sitting around watching some machines in action. It surely surpasses watching the afternoon TV programs...