(CNN)While captive for more than seven years at the infamous Hỏa Lò Prison, nicknamed the "Hanoi Hilton," in Vietnam, US Navy Admiral James Stockdale was tortured more than 20 times.
Enduring some of the harshest conditions a human can face, Stockdale led fellow service members held as prisoners of war with a thought process that combined open-eyed realism with a hope that circumstances would eventually improve.
Holding realism and idealism together is key to surviving any severe situation, whether that be imprisonment, depression or a pandemic, said author and management consultant Jim Collins, who told Stockdale's story in the popular 2001 business book "Good to Great."
In the book, Collins recounted a walk with Stockdale on the Stanford University campus decades after the officer's return from Vietnam. Stockdale had embarked on an academic career focused on the Stoic philosophers of ancient Greece.
Who was least likely to survive prison and torture?
"Oh, that's easy," Stockdale said. "The optimists." They were the prisoners who naively told themselves they would be out by Christmas, which would come and go. Then they would pin their hopes to Easter, only to be thwarted again.
"They died of a broken heart," Stockdale told Collins.
As many people face holidays shadowed by the pandemic -- many having lost loved ones and separated from friends and family, Stockdale's insights are valuable in navigating the next few months.
"The brutal facts are the brutal facts," Collins told CNN. "We won't be out of this either by Christmas."
The Stockdale Paradox
Collins crystallized this concept as the Stockdale Paradox, asserting that resilience in grim circumstances requires retaining "faith that you will prevail in the end, regardless of the difficulties." At the same time, you must confront "the most brutal facts of your current reality, whatever they may be."
For many, that means acknowledging how widespread and deadly the pandemic is while also believing that vaccines will eventually be widely available and we will get through it.
One of the best ways to seek perspectives, Collins explained, is by grounding yourself in reading about past crises, and contextualizing this moment as just part of the arc of a longer lifetime.
"This is a great time to read biographies and to read histories. Others have endured longer and harder. And it shows that we can endure longer and harder," he said.
These narratives could include how US President Abraham Lincoln grappled with depression before leading the nation through the Civil War and US President Franklin Delano Roosevelt contending with his own polio before navigating the Great Depression and World War II. Author Doris Kearns Goodwin covers the presidents and their crises in the 2018 book "Leadership: In Turbulent Times."
You could also pick up a book like Nelson Mandela's "Long Walk to Freedom," in which the South African Nobel Laureate details his life campaigning against apartheid and spending nearly three decades in prison before eventually become president of a more inclusive South Africa.
"Everybody could benefit from the zoom out," Collins said, adding that reading works such as UK prime minister Winston Churchill's memoirs of the Second World War could help assuage our own doubts about the human capacity for fortitude.
"There are other Stockdale movements that we live through," he said.
Staying resilient in difficult times
In maintaining hope for a post-pandemic future, you can harness principles from brain science, including the notion that we can feed and water our sense of hope in practical ways.
"Everything your brain is doing is in service of regulating your body," said Lisa Feldman Barrett, a professor of psychology at Northeastern University in Boston and author of "Seven and a Half Lessons About the Brain."
Socially connect: If you can't gather with relatives during the holidays, start with remembering that there are ways beyond in-person gatherings to feel connected to others.
It could be over the phone or video chat, or it could be handwriting letters or thank-you cards, but reach out to others. "You can change someone's neurochemistry around the world with just three little words," she said. A simple "I love you" can go a long way.
Simulate: Just as Stockdale shored up resilience in Vietnam by never losing sight of the "end of the story," as he said, we can tap into the brain's ability to hope through the power of imagination.
We can find solace by taking a moment to remember the smell of a hot chocolate next to an ice rink or a grandfather's laughter or the crisp wintry air at a past Christmas.
"We have this amazing brain that can do mental time travel," she said. "The past, present and future are intertwined in the brain."
Those memories trigger some of the same positive effects as the actual experience. And so can imagining a gathering in the future when the public health crisis has lessened.
Shift attention and savor: While this year has been a time of great loss, there are still many small, singular moments worth cherishing.
"The present is an ever-shifting thing," Barrett said. "You can decide to focus on some aspects of attention and ignore others."
In doing so, you essentially shift your context. Despite what may be going on around the world, you can mindfully shift your attention to the precise way your leg feels as it r