I started one of those rides last night where you realize you just shouldn't be on a bike, except it's too late and you're already fully committed.  The weather was far too nice to let the day pass without riding so I headed to the Rez for a ride after work.  For the first ¼ of the way around I felt pretty good.  I even felt pretty good on the 1½ mile slow burner up the ridge.  As I got up to the higher ground, then I started feeling funny.  About that same time, I caught up to the rider I had seen ahead on the climb.  We chatted and decided to ride together, but as we started going, I found that I wasn't clearing any of the usual features, my balance was off, my legs and arms started feeling really sluggish, and I wasn't able to respond to the trail.  I was dehydrated, my nemesis had returned.  Twice I had to stop and sit down.  The second time was rather urgent, it was a "sit down before you fall down" kind of moment.  Al (the other rider) hung with me, saying he was feeling slow too, but I'm pretty sure he just wanted to make sure I wasn't going to pass out.  This brings me to the point.  A camaraderie exists in mountain biking that is largely absent from the road biking side of things.  Two bikers in the woods are far more likely to just randomly chat, join up, and then finish a ride together and even take on a little responsibility for the safety of a stranger.  Mountain bikers will offer tools, spare parts, and general help quite freely.  I didn't need anything more than just to just chill for a few minutes while sucking down a bunch of water, but if I had been in more dire straits, there would have been someone there, and that's really awesome.

After I got my legs under me again, I started feeling much better.  As we rode on, my balance solidified and I felt generally stronger.  Turns out Al is a hell of a rider and also knew a bunch of little side trails I'd never noticed with some fairly ridiculous features.  He rolled one of the biggest drops I've ever seen another rider land in person (he was on a full-sus DH bike).  We also know some of the same people through Crankfire which is always fun to learn. After getting over that trouble at the top of the ridge, I felt great and finished the last ½ of the ride fairly strong.