A few years ago, when I first started really biking, I made a rookie mistake. Drove an hour with my wife to some trails and snapped a chain after only five minutes riding. I didn't have what I needed to fix the chain (and probably wouldn't know what to do if I did), so we walked back to the car and drove an hour home. It was then that I decided to learn to work on my own bikes and carry the proper tools.
Flash-forward to today. For the first time I did a group mtb ride with several folks I don't even really know. After only five or ten minutes of riding, the guy in front of me had his chain snap. As the rest of the group rode away, I stopped to check it out.
This guy thought his day was done, as he was new to biking and had no idea a chain could even be fixed on the trail. "No problem," I told him and pulled out my multitool, removed the bad links and put the chain back together with a spare Shimano master pin I was carrying. Within minutes we were riding again.
Now, I've done a lot of maintenance and repairs on my own bikes and have felt a real sense of accomplishment by doing so. But it was a totally different feeling seeing the gratefulness (and maybe even a bit of amazement) on this guy's face. Way cool.
It was an interesting ride though. Along with his chain, everyone else on the ride had some sort of mechanical tonight. Mine was right before I left home, when I realized my tire was flat (must have gotten a slow puncture on yesterday's ride) and had to fix it before leaving. One guy had a bent chain link that had to be replaced, another caught a tree and bent the heck out of his brake lever and dented his top tube, etc. One of the riders even had part of his tube come out of his tire. It was crazy because the tube didn't blow. It just bulged out to the size of a football.
Great ride otherwise, though.