Seneca, Moral Epistle 81.1-3
“You are complaining that you encountered someone who was ungrateful. If this is the first time, then you should be grateful to your luck or your own care. For this matter, however, care can only make you mean: if you want to avoid this kind of risk, then you won’t do people favors. So, you lose out on them, in order to prevent another wasting them.
It is better to receive no thanks than not to help people. You need to plant even after a bad harvest! Often the long term failure of unfertile soil is overcome by one season’s growth. To find one thankful person, you have to try with many ungrateful ones. No one has so perfect a hand when doing favors that they are not deceived again and again.
People should wander so they can find their way again.. Sailors try the sea after a shipwreck; an investor doesn’t flee the marketplace because of one conman. If we had to give everything up that presented danger, then life would grow boring with meaningless leisure.
But this situation should make you even kinder. For when the outcome of any event is uncertain, you need to try often to finally succeed. Well, I wrote enough about all this already in the books I wrote, under the title “On Benefits”
Quereris incidisse te in hominem ingratum. Si hoc nunc primum, age aut fortunae aut diligentiae tuae gratias. Sed nihil facere hoc loco diligentia potest nisi te malignum. Nam si hoc periculum vitare volueris, non dabis beneficia; ita ne apud alium pereant, apud te peribunt.
Non respondeant potius quam non dentur. Et post malam segetem serendum est; saepe quicquid perierat adsidua infelicis soli sterilitate, unius anni restituit ubertas. Est tanti, ut gratum invenias, experiri et ingratos. Nemo habet tam certam in beneficiis manum, ut non saepe fallatur; aberrent, ut aliquando haereant. Post naufragium maria temptantur. Faeneratorem non fugat a foro decoctor. Cito inerti otio vita torpebit, si relinquendum est, quicquid offendit; te vero benigniorem haec ipsa res faciat. Nam cuius rei eventus incertus est, id ut aliquando procedat, saepe temptandum est. Sed de isto satis multa in iis libris locuti sumus, qui de beneficiis inscribuntur.