“What soon grows old?  Gratitude.”

Aristotle, DIOGENES LAERTIUS, Lives of Eminent Philosophers, bk. V, sec. 18.

This makes sense.  Do you find it difficult to be grateful for the same blessings experienced day after day?  In order to receive our gratitude, shouldn’t each day be required to produce something more and better than the day before?  After all, if you are not growing, you are dying.