I really don't think this is the case. I gave myself permission years ago to skip a commute just because I didn't feel like riding. What's going on now is that I actually do want to ride more than I am and I'm just trying to overcome the little mental barriers that have crept into my mental processes.

As for mountain biking, that's actually a part of how my fitness slipped to where it did. I generally go through cycles of getting fat in the winter and then slightly less out of shape in the summer, but last April I was out mountain biking and broke a rib, which basically torpedoed my riding for about two months. I've decided to sell the mountain bike for my own safety. My current combination of skills (almost none) and healing ability (almost none) just don't make it a good discipline for me.