One day on the street in Washington Heights we passed an old man who invited us into his garden. Though barely the size of three parking spaces, the garden contained a vast array of unusual trees, including columnar varieties of a blue atlas cedar, a purple beech (the most magisterial of all trees), a Norway spruce, and — most impressively, for it was already 300 feet tall — a dawn redwood. These trees provided a canopy through which only the most dappled light could pass, although apparently this was enough for several species of Japanese maple to thrive, and we spent several minutes admiring the intensely variegated leaves of the most unusual specimen. Nor did we fail to note our appreciation for the delicate ferns and mythic hellebores that populated the lowest regions of the garden, or the Corsican mint that crept so luxuriantly among the crevices of the rocks. In the center of it all stood a single white birch, the golden leaves of which — for by this point it was already October — fell around us like snowflakes.

When we expressed the depths of our admiration at this display, the old man nodded. “I will give it all to you on one condition.”

“Anything,” we said without a thought.

“You must pick up each of the million twigs and leaves that fall each season, so that the bricks will stay clean and the moss will not be too invasive.”

“That doesn’t sound like much,” we responded, still eager to take him up on the offer.

He laughed somewhat wryly. “Yes, well — neither does life for the first hundred years,” he shrugged. “But when the second hundred arrive, you will know the meaning of both tedium and eternity.”