Yeah, you’ll usually get a decent lineup of dated or below average movies to watch. Certainly enough to occupy you. What I’d do if I got really, really bored is just chill out with some music. I mean, I listen to music 24/7 on a flight usually anyways, but just zoning out and thinking to music can be really nice. Also, who knows, you may get someone cool sitting next to you who you can talk with. You can meet a lot of interesting people on plane rides, and they often wouldn’t mind talking if you’re open to it.
Really, though, I wouldn’t sweat it too much. Once you’re off the plane, you’ll forget about your ride pretty quickly. It’s just another drop in the bucket. Even though it probably won’t be fun, hopefully you can make it decent enough to manage. Also, I strongly suggest you bring noise cancelling/blocking headphones or just some plain earplugs if you can. Being stuck on a long flight with a crying baby near you can be a nightmare.