It is good to return something after borrowing it.
Carl has borrowed a power tool from his neighbor for building his deck and has had it for a long time despite stopping work on the project.
Carl wants to have the right tools to finish his deck in the future.
Carl returns the tool to his neighbor and buys his own when the time comes.
Carl holds onto the power tool in case he needs it later on.
Carl's neighbor gets the tool back and saves money on purchasing a new one.
Carl's neighbor has to buy a new power tool when he needs it.