Jack Malik is a struggling singer-guitarist who is heading home on his bicycle after a singularly depressing gig when the world suffers a 12-second blackout. Besides losing two front teeth in the inevitable bus collision, everything seems fairly normal in the aftermath ... until Jack begins to realize that no one else remembers the Beatles. Nothing. Not one song.

(The Beatles aren't the only thing missing from his world; the band Oasis, Coca-Cola and cigarettes also vanished in the blip, and Saturday Night Live now takes place on a Thursday, but none of that features much in this story.)

When Jack (Himesh Patel) plays the song "Yesterday" for a couple of friends, they are blown away by his seemingly spontaneous composition. Soon, he is scrambling to remember the words and music to every Beatles song ("Eleanor Rigby" and "Being for the Benefit of Mr. Kite" are among the more problematic lyrics, apparently), and he quickly becomes famous for his "original" music.

It's quite fun watching the modern world react in Beatlemania fashion as the "new" songs are released into the wild. Of course, it's questionable if the reaction today would be the same -- the songs that were industry-changing in the 1960s might not have the same impact in a world where music has seemingly evolved along the same lines, even without the Beatles paving the way. But there's no denying their power, as the sweetly repulsive music agent Debra Hammer (Kate McKinnon) and singer Ed Sheeran (played by Ed Sheeran) -- to say nothing of countless fans across the world -- quickly realize.

But, as his success grows, Jake suffers from guilt for taking credit for the Beatles' songs, even if the Beatles themselves no longer exist in this reality -- at least, not as we know them.

That sets up one of the movie's most powerful scenes. I won't spoil it here, but Jack pays a visit to a remote seaside home for a truly memorable encounter (with an uncredited Robert Carlyle). I admit it, I got a little misty-eyed when I realized what was happening.

Patel does a really good job reinventing the iconic songs, many of which he performs just with his voice and guitar. He also handles the emotional side of his story well, both the excitement and fame as well as the rising sense of guilt, plus the inevitable romantic stuff.

Although it's not really necessary to the story, the film shoehorns in a fish-out-of-water romance that's actually quite sweet. Kudos to Lily James for taking on a thankless role -- the girl who's left behind -- and making it shine. She is Ellie Appleton: Jack's best friend, pre-fame manager and secret (to no one but Jack) love.

Also along for the ride is Rocky (Joel Fry), Jack's dim but loyal roadie. Rocky is good for some laughs, but his part seems extraneous to the story and is a bit overdone.

Ed Sheeran is a good sport, playing himself in a world where an apparent nobody is suddenly upstaging him at every turn. I'm not sure I forgive him for "Hey, Dude," though.

Admittedly, I wish the movie had taken a deeper dive into the ways music today might be different if the Beatles had never been. That, though, is difficult to predict, and I can see why filmmakers avoided that particular storyline -- but damn, think how much fun it would have been to conceive and build that particular world for the movie.

Even so, Yesterday is fun, sweet movie that I thoroughly enjoyed watching ... and it has had me humming Beatles tunes ever since.