Your bookshelf, in your pocket. And in every AI you use.

Pick up a cushion of moss in August, after three weeks without rain, and it crumbles like old paper. Most plants would be dead by then. The moss is only waiting. It has no roots to draw water from deep soil and no waxy skin to hold water in, so it does the opposite of holding on: it lets itself dry out almost completely, shutting down in an orderly way as it goes. Botanists call this desiccation tolerance, a dry phrase for something close to a magic trick.

Add water and the trick runs backward. Within minutes the leaves unfold and turn from brown to green; within an hour or so, many species are making sugar again. Specimens kept for years in dry herbarium drawers have been brought back this way, and in 2014 researchers regrew moss from Antarctic peat that had been frozen for more than fifteen hundred years.

I find this a useful thing to know in a bad week. The moss is not being brave. It simply doesn't spend what it doesn't have. It waits for rain with its whole body, and when the rain comes, it is ready.