I just love riding, and do not tend to get caught up in the macho "I can ride better than you can!" environment when I'm out with buddies or alone....I absolutely will not answer a challenge, most of the time I'll just say, "You guys go on ahead, I'm just here to enjoy the ride and the scenery...."
Sometimes the entire day's ride is from my place to work and then back home, sometimes it's 4 hours, 6 hours or 8 hours to some remote location, then hang out in the hotel pool and get some R & R, then back home the next day...all done at my own pace, enjoying the 2 wheels the entire way....