He who has received a kindness forgets it; he who has been injured remembers it. (Latin Proverb)
He who has received a kindness forgets it; he who has been injured remembers it. [To benefit one and injure another at the same time is a losing game, for revenge is a stronger feeling than gratitude.] (Latin Proverb)
No thanks attach to a kindness long deferred. (Latin Proverb)
How quickly with all is a kindness forgotten! (Latin Proverb)