Lin-Manuel Miranda on the power of art during COVID-19, other lessons learned in 2020

In a cozy sweater perfectly appropriate for the chilly December weather and stay-at-home comfort theme of the year, Lin-Manuel Miranda took some time to reflect on 2020 with ABC News, from the highs and lows to finding the silver linings amid the chaos.

As the coronavirus began spreading in the United States, Miranda said he was so "laser-focused" on his work directing his first feature film, "Tick, Tick… Boom!" that he didn't realize the forthcoming crisis. He credited his wife, Vanessa Nadal, a lawyer with a chemical engineering degree from the Massachusetts Institute of Technology, with having the foresight to prepare.

"The greatest blessing of my life is that I'm married to a woman that is much smarter than me, and she really kind of saw the trend of how COVID was spreading and said we've got to be ready… We've got to take measures so we can be safe," he told ABC News' "The Year: 2020." "And so I'm grateful to her for that. She got us through the year."

Miranda said they spent March "figuring out what the new normal is. ...Figuring out the new procedures when you leave the apartment and what happens when you come home, the best ways to stay safe when you go out."

As they settled in, Miranda said they made sure to entertain themselves with a variety of TV shows and docuseries. But he also said he felt compelled to keep other people entertained.

Watch "The Year" on Tuesday, Dec. 29, at 9 p.m. ET on ABC.

In March, he received a text message from "A Quiet Place" star John Krasinski about reuniting the original cast of "Hamilton" on Krasinski's YouTube show "Some Good News" to surprise 9-year-old superfan Aubrey Bauman.

"It was joyous," Miranda said. "Remember, this was all before we'd even decided to release Hamilton [on Disney+]. So, we hadn't gotten together as a collective in a very long time, probably since we were first on Broadway in 2016. … The goal was to lift people's spirits. Everyone said yes so fast."

Miranda and Disney chairman Bob Iger announced in May that "Hamilton," the musical film, would be available for streaming on Disney+ just before the Fourth of July. When it was released, he said he stayed up long past midnight just to see people's reactions in real-time.

"I got online just to watch people watching it and reacting on social media," he said. "I knew that more people would see it on the Friday it came out than in the previous five years, and that's really exciting."

While Miranda said the launch to streaming increased peoples' appetite for the musical, he also acknowledged what he'd previously called "valid" criticisms following the film's release. The musical about the nation's founding fathers, which was filmed live in 2016, had been called out and accused of glorifying slave owners.

"You have to contend with these characters as flawed, which is the way I believe we portrayed them, and they're all participants, active or passive, in this original sin of slavery that continues to have lasting repercussions in this country," he said. "And so, having more critical conversations about the founders that inspired these characters was a part of that conversation."

Miranda said he spent lots of time this year on Zoom, including dropping in on fans' "Hamilton"-themed Zoom parties. He even engaged with legendary composer Andrew Lloyd Webber in a piano play-off on Twitter in hopes of raising money for the out-of-work entertainment community.

He said it was all about "making people smile" and reminding people of "how important the arts are to our world."

"We never think of them as important, but try to imagine 2020 without being able to read those books or watch that show or watch those films, or have art inform your life when you have to be home or when you've had a hard day?" Miranda said. "We look to it for catharsis and for relief, and it's been an incredible reminder of the power of art because we've really needed to lean on it this year."

Miranda called 2020 "revelatory" for all the strengths and weaknesses it exposed within the U.S.

"One of the lasting legacies of 2020 is that we really learned who's essential," he said. "Not just our front-line workers, but those small businesses, those delivery men, those postal workers, UPS delivery, FedEx delivery guys -- the folks who keep the world moving, even when we have to stay home. They've got to go out and often, they're the more vulnerable among us."

"And so, I hope that we go into 2021 with a reminder that those folks kept us moving when we couldn't move, and they deserve every resource possible because in many instances, they saved us and kept our country running," he added.

He also commended health care workers on the front lines, who he said have gone through the "impossible" and "unimaginable" with "incredible resilience."

"Tragically, there were so many places with limited supplies and scant resources. … I think the best thing we can do in addition to staying safe is paying them a living wage and give them the resources they need to keep us [safe]."

He said a silver lining of the strain placed on essential workers was seeing the number of everyday people rallying around them.

"I know that at 7 o'clock [at night] every day in New York City, most of the year, we've been cheering our essential workers, our front-line workers," he said.

The best way to continue honoring them is to "continue to observe what is scientifically proven to keep us safe: wear masks when you enter a place of business or crowded area. Stay home when you can," he said.

Miranda also encouraged people not to be too hard on themselves as the year comes to a close. Many people might've pressure to accomplish projects big or small while staying home. Miranda said he turned to his keyboard and started writing new music when the lockdown began, but it was hard for him, too.

"I don't want it to seem like, 'Oh, I had this incredibly productive time,'" he said. "Like, you're allowed to process the fact that the world has changed and is changing. That brings a whole range of emotions … a whole range of adjustments. If you didn't write 'King Lear,' it's OK. I didn't."

"I did what I could once I wrapped my head around the new normal," he added. "But it's also important to allow for your mental health. It's important to allow for the many changes that this year has brought, and tending to those things before you beat yourself up."

Disney is the parent company of ABC News.