An ungrateful man is like a hog under a tree eating acorns, but never looking up to see where they come from

One ungrateful man does an injury to all who are suffering. [Lat., Ingratus unus miseris omnibus nocet.]

All the stored vengeances of heaven fall On her ingrateful top!

This was the most unkindest cut of all; For when the noble Caesar saw him stab, Ingratitude, more strong than traitor's arms, Quite vanquished him. Then burst his mighty heart; And in his mantle muffling up his face, Even at the base of Pompey's statue (Which all the while ran blood) great Caesar fell.

Ingratitude is monstrous; and for the multitude to be ingrateful were to make a monster of the multitude; of which we being members, should bring ourselves to be monstrous members.

Ingratitude's a weed of every clime, It thrives too fast at first, but fades in time.