In reality, this is the essence of consideration in law. If someone gives you something, such as a promise, money, forbearance, services or the like to which you were not entitled such would constitute valid consideration. And you would need to reciprocate. Consideration is something that has value. It is generally defined as a benefit conferred or a detriment incurred at the behest of the other party.
Consideration is more than a mere gift.
More than morals. It represents a mutual interest. It is also referred to a quid pro quo , what for what, and the benefit of the bargain. Exceptions are prevalent such as common law sealed instruments and promissory estoppel. The Uniform Commercial Code also provides for firm offers, modifications, etc. without the requirement of consideration.