That depends on what you define as selfless. What if the "return" is simply a feeling of joy for having helped a fellow human?
Random acts of kindness occur more often than people think. For example, a friend of mine borrowed a chiller fan from local businessman, found that it needed a new pump, bought the $50 part and fixed it so it could be used. The establishment that he was using it in later burned to the ground. He went to the businessman, that he borrowed the fan from, and explained the situation, offering to pay for the fan's replacement cost and asked what would be an acceptable amount.
The lender said that he would accept no payment, thanked my friend for his honesty, offered him condolences for his losses, due to the fire, and stated that he could never recall anyone making such an offer to him before. The lender then said that he was a bit upset that the loaned fan was not kept in proper working order, since he pays his employees well to ensure that his equipment (used for his business) is in good working order, and recalled that on several prior occasions in which equipment/tools that he had loaned were said to have "broken down" and they were either returned in unusable condition or the lendee had actually expected reimbursement to cover their repair costs.