When I had one Lionel train as a kid, I didn't dare screw it up because I knew I'd never get another.
When I was into HO as a teen, it was all track power, everything moved the same direction and speed, so crashing anything never came to mind then.
Now that I have On30 with DCC, I could now have a 'cornfield meet' but now I'm back to the original concept that it'd be tough to explain to my wife why I need new parts for one of my ten-wheelers after the crash as the detail parts up front are pretty fragile, I'd think.
Also, I had my fill on destroying things on your tax dollars through the Army.