Exercise is not 'fun' for me. I do not do it because I enjoy it. I do it because I am supposed to; it is theoretically good for my physical and (especially) mental health.
I wake up every gym day disappointed that I have no excuse to skipping it. I have apparently improved notably over the last couple of years, but I feel like I am essentially in the same place I have been for a decade or more. There have been multiple times that I have wished for a truck to hit me so I wouldn't have to get up and go.
Honestly, my next step is probably to do the same thing with dieting to be healthier, although since eating is actually enjoyable, I haven't gotten there yet.
Sorry to be a little Debbie downer!