Mary at WPL recommended Lev Grossman’s The Magicians years ago but I shied away, mainly because I thought it was going to require a deep love of Narnia, which I do not have. It didn’t, though the Narnian parallels are important. (Here the magical world is called Fillory and is a bit different, for story purposes.)
In the novel the main character is a disaffected snotty upperclass teen who loved the Fillory books. He’s about to graduate from high school when he receives a mysterious invitation to attend magic school. He passes the gruelling examination and learns to be a magician in the first part of the book. Honestly, I wasn’t a fan early on. It felt too much like Harry Potter but with more drinking and cussing. Once they’re out of school though, the book really picked up. Then it became a story about figuring out what to do with yourself when you can do anything.
The tedium of learning magic was conveyed really well and there were some very good worldbuilding things. The whole thing built to an appropriate climax, which seemed inevitable even as it wasn’t completely expected. I’d generally recommend this one. There’s a sequel out now, but I’m not rushing to read it, as I liked where this ended.