I'm about the same age and LOVE noticing the same things. I don't love that we've lost all those miles of rails. But it is a minor "fun" thing to notice while around the countryside is where the old RR lines ran. My GF thinks it's amusing that we're just passing through a random small town and I'll go "old railroad" and just keep on going 

Yes, the angled roads in small towns, buildings at weird angles, old elevators and bins, all sorts of tells. I've spent HOURS on google maps and such following old RR lines and seeing if I can follow their route. The older ones are tough when they've been farmed in lots of places for years but you can still see hints here and there.