I think that’s the wrong takeaway - the point is that when it’s happening to someone else, it’s easier to see the ‘right’ attitude to take regarding misfortune.

Of course it’s awful to have your child die, but also it’s fairly commonly understood, that it can’t be the end of your life as well, you take the time you need to grieve, and then you go on living. “So it goes.”

The point with the cup is the same: it’s easier to council patience and forgiveness when your lap isn’t soaked with wine, when shards of your cup don’t litter the floor.

It’s demonstrating a route to removing yourself from the emotion of the present situation, to examine things rationally, dispassionately, like you would if they were happening to someone else, because it’s easier to see the right thing to do that way.