My main motivation is health. Second is seeing myself get better. I also enjoy setting goals and meeting them. I have a yearly milage goal I'm hoping to hit. also have monthly goals. Yesterday I wasn't totally motivated to go ride but I was 20 miles short of my goal of 600 for the month so I went for a ride. Clearly it was motivation enough. Oh, and so far, I've done all my miles solo which is about 5500 since in started about 20 months ago. I enjoy the freedom of solo rides: go when I want, where I want, as fast or slow as I want, change mid-ride as I want, etc.