I don't ride alone much except as a utility rider. That only represents about 5 to 10 percent of my riding time. Centuries I ride with friends and I pay because most often the proceeds go to worthy causes. I might ride 100 miles by myself but it is to get to someplace specific, like a meetup to ride with friends. I hardly ever just wander more than 20 miles or so just for the sake of wandering. So a 100+ mile ride by myself isn't a century it is just a trip like driving to Colorado, just my perspective. Sometimes when riding from Long Beach to San Diego I will ride with my group of friends on maybe pull up to another group and chat between cities. I guess I find people more interesting than bushes and dirt and pavement.