What's your take on racing strangers without them knowing it?

I do it, probably more than is wise but hey, who knew! Okay here’s what i’m getting at, there are a variety of ways to indulge in a “stealth race” with persons you happen to see while you’re out & about. You could if you’ve a mind to, quicken your pace while walking in order to beat a fellow pedestrian on the other side of the road. Oh yeah, you can even manufacture a finish line, a road sign or a street light making ideal winning posts. When you’re shopping it can be a lot of fun to race your kart/trolley with an unsuspecting shopper. Yes it may be a hollow victory seeing though they’re unaware of your madness…...tomfoolery. Can still be rewarding in it’s own little way though. So, stealth racing with strangers. You game?