If you’re worried about losing your mind during lockdown, here’s some advice from an expert: don’t be an optimist.

Admiral Jim Stockdale was held in the “Hanoi Hilton” prison camp for seven years, where he was tortured more than twenty times. He says he came out of the camp stronger than when he went in. Speaking to Jim Collins, he explained:

I never ever wavered in my absolute faith that not only would I prevail—get out of this—but I would also prevail by turning it into the defining event of my life that would make me a stronger and better person.

When Collins asked him about the people who didn’t survive so well, Stockdale answered:

I can tell you who didn’t make it out. It was the optimists… They were the ones who always said, ‘We’re going to be out by Christmas.’ Christmas would come and it would go. And there would be another Christmas. And they died of a broken heart.”

Of course, being in lockdown in a nice house or flat is hardly the same as being a prisoner of war. But Stockdale’s argument is a sound one. To take a slightly less impressive character, John Cleese’s headmaster in the 1986 film Clockwise:

It’s not the despair, Laura. I can take the despair. It’s the hope I can’t stand.

Or perhaps you prefer Stephen King? Here’s a bit from his novel Joyland:

You think Okay, I get it, I’m prepared for the worst, but you hold out that small hope, see, and that’s what fucks you up. That’s what kills you.

I’m not suggesting we should all go around in abject misery, weeping and wailing and gnashing our teeth. But I do think that focusing on anything that is not within our control is going to be bad for our mental health. For example, if you were hoping that the lockdown would be lifted last week, how did you feel when it was extended? How will you feel if it’s extended again?

Stockdale:

This is what I learned from those years in the prison camp, where all those constraints just were oppressive. You must never ever ever confuse, on the one hand, the need for absolute, unwavering faith that you can prevail despite those constraints with, on the other hand, the need for the discipline to begin by confronting the brutal facts, whatever they are. We’re not getting out of here by Christmas.