You should always return things to their rightful owner.
Mike is an Uber driver, and his last passenger left their wallet in his car.
Mike has to decide whether to give the wallet back.
Mike drives all the way to the passenger's house to give the wallet back.
Mike decides to keep the wallet and tells the passenger he didn't find it.
The passenger feels grateful and no longer has to worry about it.
The passenger has to wait to get another licence and loses any money in it.