My partner mentioned to me the other day, "I should rewatch the Harry Potter movies again." And I thought that was a great idea, minus the 20-ish hours required.
Fortunately, there's a better way.
Courtesy of Tim Stiefler and Entertainment Weekly, Wizardhood is the 80 minute wonder every Harry Potter-loving adult needs. It's basically an 90 minute supercut of the entire series, minus Fantastic Beasts, leaving nothing but the most important elements.
You do miss out on a good deal of the worldbuilding that makes the Harry Potter franchise so engaging - particularly in the first three films - but even with that in mind, 90 minutes usually beats out 20 hours any day. It's free to watch on Vimeo right now, although sadly the video caps out at a maximum of 720p.
As a random bonus, reading through the comments has now taught me that Star Wars: Neon Noir exists. That's a fan cut of the first three Star Wars episodes which, let's face it, nobody should have to watch through again in their entirety. (Except for the Yoda/Count Dooku fight, that's always worth rewatching in full.