//: The average person walks 100,000 miles in their lifetime//
I would dispute that. Assuming an average "walking" lifetime of, say, 70 years, it would suggest the average distance covered is around thirty miles each and every week - over four miles each and every day. Some people may do that; some may even do more than that. But I would suggest that the vast majority of people do nothing like that over their lifetime.
//...that’s three laps around the world.//
It's four. The Earth has a circumference of just under 25,000 miles.