Being a movie critic is the best job in the world. You get paid to watch films and, even better, to discuss them endlessly in a running dialogue with readers. I would never complain about the best job in the world, but it does have a down side. Keeping up with the latest releases, in theaters and on DVD, is an enormous, time-sucking task, so I rarely had the opportunity to go back and revisit old favorites.

As a kid, I was a voracious consumer of classic film. My tastes were cultivated by parents who weren’t afraid of movies shot in black and white or made before the ’80s. My grandmother would call us to her room to watch musicals like “My Fair Lady,” “Singin’ in the Rain” and that charming duo, Ginger Rogers and Fred Astaire. The result was that my little brother became obsessed with tuxedos, my parents were forced to listen to our renditions of show tunes on a loop during car trips and my siblings and I developed an enduring love for the classics.

That love never disappeared but it diminished during the 13 years I spent as film critic for a local newspaper. Sitting down and revisiting a gem made more than 30 years ago was a luxury of time I could rarely afford. Sometimes I’d fantasize that my boss would insist I take a year-long sabbatical to do nothing but watch Turner Classic Movies. That never happened while I was at the paper, but the fantasy did come true in an unexpected way.

At the end of December, I had a baby, a daughter who, as most infants do, required constant care through the wee hours of the night. As a new parent, I was subjected to a level of sleep deprivation so intense it made my head spin. Since my husband was working to keep that little mouth fed, I was on night shift and, let me tell you, those were some long nights. As any insomniac knows, there is no loneliness as profound as the loneliness of being awake after 2 a.m. As delightful as my new baby was, as I sat with her in my arms in the darkened living room, it was all too easy to cave in to the enveloping blackness, a despair that the morning would never come. I felt like I was the only person left in the world.

When I remembered Turner Classic Movies, the cable channel that shows vintage flicks all day and all night, a light broke through the gloom. My husband was bemused to see our DVR fill up with 1930s screwball comedies, war pictures and Westerns, Technicolor musicals, black and white melodramas, cheesy sci-fi oddities and legendary foreign films from the 1960s and ’70s — whatever struck my fancy when I stood at 4 a.m., blinking bleary-eyed at the television screen.

Hosts Robert Osborne and Ben Mankiewicz became my best friends. The chiming sound of the late-night TCM promo was a cheerful beacon, cutting through my mental fog. I felt like a human being again. And I learned a lot.

I realized that I had never really paused to appreciate Sidney Poitier and his graceful mastery of acting. After a marathon of “The Defiant Ones,” “In the Heat of the Night,” “Lilies of the Field” and “The Slender Thread” — in which he spends most of the film on the phone with Anne Bancroft, trying to talk her out of suicide — I was left dazzled by his dignity and playfulness.

I rewatched 1947’s “The Secret Life of Walter Mitty,” a childhood favorite that is an entirely different animal from Ben Stiller’s recent, surprisingly wonderful remake, and laughed aloud at Danny Kaye’s physical comedy antics. A scene in which Mitty struggles awkwardly to move a chair while holding a teacup should be among the most celebrated moments in comedy, but I fear few people have even seen the film.

Diving into the deep end once again with that swimsuit-clad goddess — Esther Williams — a favorite of my grandmother, I marveled at how much bang these classics gave audiences for their buck. It wasn’t enough to simply tell moviegoers a good story, these films also delivered numbers conducted by famous orchestra leaders, solos by jazz or opera singers, tap dancing interludes or an elegant ballroom dance, a choreographed water ballet or a fashion show. The clothes were stunning. The settings were exotic. These were the days when people got dressed up to go to the movies and the studios were careful to give audiences what they wanted. Hollywood really knew how to put on a show.

What else did I learn during my late nights with TCM?

Everyone wore the most fabulous negligees to bed and the men wore ridiculous smoking jackets over their shirts and pants. Myrna Loy, Joan Crawford and every other leading lady worth her salt could not drift off to sleep unless she was swathed in a feminine cloud of silk, tulle, ribbons and lace.

I remembered why I love Doris Day movies, all that pert, wholesome perkiness mixed, like a dry martini, with ribald sexual innuendo. In contrast, as an adult, I found the beloved screwball comedy “His Girl Friday,” starring Cary Grant and Rosalind Russell, to be much darker and more problematic than I recalled, a scathing but weirdly blithe indictment of media carelessness.

I discovered the rakish charms of Melvyn Douglas, a suavely mustachioed screwball comedy king who starred opposite Greta Garbo in 1939’s “Ninotchka.” I was struck again by the blistering chemistry of the radiant Katharine Hepburn and her on and off screen love, the rumpled but sexy Spencer Tracy. I never knew that Jimmy Stewart actually sang and tap-danced — albeit it briefly — in the 1936 Cole Porter musical “Born to Dance.” He wasn’t half bad.

I watched Rosalind Russell vamp it up in “Auntie Mame” for the first time ever. How is it possible that I existed without seeing this sublime comedy?

Other firsts for me included “The Red Shoes,” the phantasmagorical masterpiece that influenced Darren Aronofsky’s “Black Swan,” “The Umbrellas of Cherbourg,” with its mouth-watering production design, “The Bicycle Thief,” which crushed me with just about the saddest ending ever.

What I learned most of all is that the films of Hollywood’s heritage are indeed glorious. They are called “classic” for a reason. That isn’t to say they’re perfect. One of the things that astonished me was the rampant sexism and racism of Golden Age films, in which women are routinely punished for desiring a career over a husband and minorities are resigned to play dim-witted servants.

Despite their flaws, these movies have endured for decades, passed from one generation to the next like treasured artifacts. Scholars have attributed their magnificence to the great studio system that spawned them, to superior methods of writing, acting, filming and composing. Whatever the reason for their success, I think what makes an old movie truly great is not that it was shot in beautiful black and white or stars a timeless legend. It’s that the movie nudges us into feeling something deeply.

One particular lonely night spent with TCM stands out to me among the dozens and dozens of lonely nights. I was watching “Singin’ in the Rain,” lulling my baby to sleep to the watery sounds of the title song.

“What a glorious feeling. I’m happy again,” sang Gene Kelly, swinging himself around the lamppost in a scene that has been viewed millions of times by millions of people.

Once again, Gene Kelly splashed in a puddle. Once again, he sang. My heavy heart lifted.