Travelers

Why do people feed travelers? I haven't experienced this very much on a first-hand basis, but I get the impression that people are eager to feed someone who is passing through, on some kind of journey. Is it that deep down we understand that life itself is a journey and that we are all traveling in our own way? Is it simply that we all wish we were traveling instead of being stuck in one place, so we try to live vicariously through the travelers we encounter, and we help them along and hope they succeed?