“If you in the morning
Throw minutes away,
You can't pick them up
In the course of a day.
You may hurry and scurry,
And flurry and worry,
You've lost them forever,
Forever and aye.”

Source: Adverbs

Source: His Dark Materials, The Subtle Knife (1997), Ch. 15 : Bloodmoss
Context: If you're the bearer of the knife, you have a task that's greater than you can imagine. A child... How could they let it happen? Well, so it must be.... There is a war coming, boy. The greatest war there ever was. Something like it happened before, and this time the right side must win. We've had nothing but lies and propaganda and cruelty and deceit for all the thousands of years of human history. It's time we started again, but properly this time...."
He stopped to take in several rattling breaths.
"The knife," he went on after a minute. "They never knew what they were making, those old philosophers. They invented a device that could split open the very smallest particles of matter, and they used it to steal candy. They had no idea that they'd made the one weapon in all the universes that could defeat the tyrant. The Authority. God. The rebel angels fell because they didn't have anything like the knife; but now..."
"I didn't want it! I don't want it now!" Will cried. "If you want it, you can have it! I hate it, and I hate what it does — "
"Too late. You haven't any choice: you're the bearer. It's picked you out. And, what's more, they know you've got it; and if you don't use it against them, they'll tear it from your hands and use it against the rest of us, forever and ever."

Variant: every moment you steal from the present is a moment you have lost for ever. There's only now.
Source: The Passion

Source: The Great Gatsby

The Dance of the Hours
Don Camillo and the Prodigal Sun (1952)

Source: By the Time You Read This, I'll Be Dead

"Lear, Tolstoy and the Fool," Polemic (March 1947)
Context: Shakespeare starts by assuming that to make yourself powerless is to invite an attack. This does not mean that everyone will turn against you (Kent and the Fool stand by Lear from first to last), but in all probability someone will. If you throw away your weapons, some less scrupulous person will pick them up. If you turn the other cheek, you will get a harder blow on it than you got on the first one. This does not always happen, but it is to be expected, and you ought not to complain if it does happen. The second blow is, so to speak, part of the act of turning the other cheek. First of all, therefore, there is the vulgar, common-sense moral drawn by the Fool: "Don't relinquish power, don't give away your lands." But there is also another moral. Shakespeare never utters it in so many words, and it does not very much matter whether he was fully aware of it. It is contained in the story, which, after all, he made up, or altered to suit his purposes. It is: "Give away your lands if you want to, but don't expect to gain happiness by doing so. Probably you won't gain happiness. If you live for others, you must live for others, and not as a roundabout way of getting an advantage for yourself."

Variant: There are many things that we would throw away if we were not afraid that others might pick them up.

Source: The Giver