Something one person loses or discards something, it gives another person the chance to claim it or take advantage of the situation. I heard ADS Advertising lost the FlemCorp account, which means we've got a shot of taking it over for ourselves. One person's loss is another person's gain! I was walking home from my night class when I stumbled across a perfectly good bicycle lying on the street. "One person's loss is another person's gain," I thought to myself, as I picked it up and rode it the rest of the way home.