Seneca, Epistulae Morales I

I’m a little confused with a sentence of Seneca’s and I wanted to see what you all thought:

[3] Dum differtur vita transcurrit. Omnia, Lucili, aliena sunt, tempus tantum nostrum est; in huius rei unius fugacis ac lubricae possessionem natura nos misit, ex qua expellit quicumque vult. Et tanta stultitia mortalium est ut quae minima et vilissima sunt, certe reparabilia, > imputari sibi cum impetravere patiantur, nemo se iudicet quicquam debere qui tempus accepit, cum interim hoc unum est quod ne gratus quidem potest reddere.

I’m thinking “And such is the stupidity of mortal men that those things which are smallest and most worthless, and certainly replaceable, when they [mortals] have acquired them, they [the things] are allowed to be attributed to one’s self, [although] nobody would judge himself to owe anything who takes/passes time, when this is the one thing which he cannot happily restore.”

The subjunctives for “patiantur” and “iudicet” are tripping me up. As are a number of constructions like “imputari sibi” and “tempus accepit.” Also, I’m not sure what to make of “gratus” in this context. Is it functioning adverbially?

Salve thesaure,

And such is the stupidity of mortal men that they would allow the slightest and cheapest things, which are certainly replaceable, to be charged to them when they have acquired them, [but] no one who has received Time would judge that he owes anything whatsoever, while at the same time this is the one thing that > not even a grateful person > can pay back.

Du usu subjunctivi in hôc loco, vide A&G, §571.

Gratias tibi ago, Adriane, qui mihi indicium de usu subjunctivi das.

Sed etiam nunc nescio quid significet “imputari sibi patiantur.” Quid significat “cheapest things are charged to them”? What is being charged?

Fortasse etiam ita (haud stricte)verti potest? “They allow themselves to feel responsible for the least important things once they have acquired them, although nobody feels himself responsible for the time he has taken…”

charged to them = to mortals, put onto their account = sibi, id est, mortalibus
“[quae vilissima] imputari sibi patiantur.” = “they [mortals] would allow [some of] the cheapest/most worthless things to be charged to them [put on their accounts as debts to be paid]”

Three verbs and an adjective connected to money and trade: imputare, debere, reddere, vilis. We put a price on even the most worthless things. How stupid to treat Time as less than worthless when it is beyond price.

Habes verba tria ac adjectivum quod negotium et pecuniam spectant. Vilissima quidem aestimamus. Quam stultum ideò est tempus ut minùs vile aestimare cum verò inaestimabile.

http://www.archive.org/details/adluciliumepistu01seneuoft Epistle 1, vol. 1, p.5 Seneca (4 B.C. - A.D. 65) - Lucius Annaeus Seneca LOEB Classics Translation (Latin/English)