How long is eternity

“That takes forever again,” complains Erika. She is stuck in a traffic jam with Erwin on Friday afternoon heading out of town. Somewhere it doesn't go any further.
"It won't be an accident, it can take a while."
“We'll be standing here for maybe five minutes,” says Erwin.
"Half an eternity and nothing moves."
“Five minutes - half an eternity? And an eternity, that would be ten minutes, right? "
Erika rolls her eyes.
A police car drives past them with flashing lights.
“Oh dear,” says Erika, “but an accident. The poor people, I don't want to say anything if I'm stuck in a traffic jam for a few minutes. "
“Not an eternity? Have you ever thought about what that is, eternity? "
"Sure, there is a story," says Erika. “Eternity is like a great mountain of diamonds. And every thousand years a bird comes and whets its beak on it, once, and when the mountain is worn away by the beak whet - then the first second of eternity has passed. "
“That is very nice, but unfortunately your story has a mistake in reasoning. It sounds like eternity is made up of time. "
"Yes, what else? Probably not made of diamond. "
Erwin cannot be brought out of it. “That is a very horrible idea - that it will go on and on. Like the jokes about heaven. That you sit forever as an angel with a harp on the cloud and how boring it has to get and how you can endure it. "
“I've always found these jokes stupid,” says Erika.
“I think,” says Erwin, “we can't really imagine it because we can't imagine a life without time. But I think eternity is without time. Then time simply doesn't matter anymore. "
“And we are often so impatient,” says Erika, “because we always think we don't have enough time. Oh, I think it will continue up there. "
“Yes,” he says, “our minds quickly reach their limits. All we can imagine is just ... "
He's running out of words. They are also driving past the scene of the accident. Fortunately, not much seems to have happened.
"Yes," says Erika, "all we can imagine is just a very small sharpening of the beak on a mountain made of diamond, from a bird that only comes by every thousand years - like that?"
He looks over at her. Has she had the last word again! But this time she deserves it.