Anybody have any advice for staying motivated through a long term recovery?

I've been training parkour, gymnastics and capoeira as well as going to the gym at work for cardio and some weight training. But in December I finally had to give in to reality and have a major knee surgery where they implanted new cartilage in my knee. I'm through the worst of the post surgery pain and am working on range of motion exercises and leg raises etc.

The recovery is estimated to be another 12 to 14 more months. During which, I won't be able to jump, run, land or twist. In other words, every day is upper body and core strength day for the foreseeable future.

I knew what I was getting into with the surgery, but I'm not sure how to stay motivated to do what I can for that long a period where I won't be able to do the things I find fun. Not doing anything isn't an option, both because I'd go crazy and I'd never be able to pick it all back up again if I stop for more than a year.

But the upper body stuff doesn't really interest me as it's generally more static rather than movement based. Any ideas on staying motivated?