This Tuesday at sundown, millions of people around the world will participate in a dress rehearsal for their deaths.

They will abstain from eating and drinking and making love, since corpses can do none of those things. They will utter a variation of the confessional that they will say on their death beds. And many of them will wear white, like the shrouds they will be buried in.

I’ll be one of them.

Most people, including many Jews, think of Yom Kippur as a 25-hour caffeine headache capped off by a lox-and-bagels binge. It’s undeniably that.

But it is also, at its deepest level, a dry run. It is the one day of the year when we Jews are asked to look our mortality in the face.