I like to change up the pace almost every ride. My main reason for cycling is simply because I love riding bikes. The mental outlet aspect of it is at least as important to me as the physical aspect. Some times, I am suddenly struck with the desire and need for speed, some times to just stop and get off the bike for a few moments. I no longer pay much attention to average speed and on bike time, but I do still keep a fairly accurate running total of miles in my head. Other than just getting on a bike and riding, by main concerns are comfort and enjoying the ride. I am pleased and grateful to be able to ride at the level I do, whatever that level is.