Back in 1994 when I lived in Oakland, California for a year, I picked up a free, locally printed cycling magazine at a bike shop in Berkeley. It had an article about single-speeding and I was intrigued. Fresh out of college spending a language year on the little savings I had made during a short, temporary design job in the medical industry, I had a nice mountain bike - a very nice one in fact - but certainly not the cash to build a single-speed as a second bike. Several years passed in which I returned to Switzerland, worked as an engineer then moved to California to start another job. Once I got established and managed to save a bit of cash, I ultimately built my first single-speed.
Well, I was hooked and never looked back. A single-speed on Northern California's dusty single trails was a lot of fun. So much fun in fact, that it didn't take long until I also converted my geared mountain bike to one gear. Early on, I had a hardtail with a RockShox suspension fork up front. In the mid-90s, I owned a rigid McMahon Titanium fork, which I had traded in for a suspension fork at my LBS in Switzerland. Every time I visited, I stopped at the shop and for years my fork was hanging there in the shop. One year, it was gone so I asked if someone finally purchased the thing. No, was the answer. No one had shown any interest in years, so it went to the basement. I bought it back that day and since then all my bikes have been rigid.
Riding with just one gear and with no suspension has made me a better and, I believe, a stronger rider. A rigid fork requires picking perfect lines and does not forgive the slightest mistake. There's no way to take it easy pushing one gear uphill; either the legs bring the power to the pedals or I walk. It brought the challenge back that went lost in the arms race for ever more gears. A rigid single-speed changed the way I read and attack a trail, too.
One gear and no suspension was and is also a lot about simplicity. There are few parts needing maintenance, fewer parts that need cleaning, and other than a pair of brakes, there's nothing that needs adjustment. Still today, this is one of the things I appreciate a lot about my single-speed. In fact, I'd be horrified to own a geared full-suspension bike. I've never owned one and likely never will. I just don't want to deal with all the extra pivots, linkages, shocks, and whatnot. Besides, looking at the service intervals for forks and shocks it seems like one has to tear them apart several times a year or worse send them in to be serviced. Not my kind of thing.