It is absolutely not overkill. Think of all the things you “should” be doing with your free time. Do any of those provide as much stimulation or joy as sitting down for two-and-a-half uninterrupted hours dissecting a piece of art? I absolutely love watching movies multiple times for exactly the same reasons you mentioned. You can really pay attention to different things each time, and, consequently, you may notice something you never had before. A truly great piece of art will always have something new to give you, even if you’ve seen it 99 times before.
…Also, MoviePass. It’s a wallet saver for those of us that still love the theater experience.