You probably didn't mean it, but it sounds like you're saying you don't understand why anyone could have trouble walking three miles? In case that's actually wh

You probably didn't mean it, but it sounds like you're saying you don't understand why anyone could have trouble walking three miles? In case that's actually what you meant, then some of the reasons include disabilities (whether temporary like a broken leg, or permanent like arthritis), organizational constraints like having a small child with you, time constraints, or unsafe environments for the walk.