When I got back into cycling after after not riding for more than a decade, I stumbled onto Sheldon Brown's writings about fixed-gears and was intrigued. Then
I read this article by Peter Moore on the old twowheelfetish site (thank you, Internet Archive!) and something clicked into place for me. I built my first fixed-gear with a late 50s Raleigh Lenton Grand Prix, which was supplanted by a series of road conversions - a (dented) Gitane Super Corsa, a Trek 620, a Peugeot PR-10L, a Falcon San Remo, then a c.1971 Raleigh Competition (which, had I known then what I know now, I would have kept!). I bought one of the first Bianchi Eco Pistas in 1999, sold it after a crash due to a faulty clipless pedal spontaneously releasing - but I missed riding fixed gears. I splurged on a custom Mercian Vincitore, designed to be a modern interpretation of a vintage British club bike - and if I could do it over again, I would have specified clearance for 32 mm tires with fenders and loooong "horizontal" front-facing road dropouts to play better with a rear brake.
I rode that Mercian for thousands of miles and loved it. It was my primary bike for more than a decade, and it may become that again for me. I traveled pavement, dirt and gravel roads on 28 mm tires, alone and with select trusted friends. All the while, the raw, primal, elemental quality of riding fixed fed something in me. I spend much of my day working on a computer screen cataloging other people's words and mucking around with symbols. Riding a bike is good, but riding fixed was just a little bit more real, and it's akin to playing an acoustic guitar with your bare hands and no picks, just a sensation of greater connection and contact. There is no shifting, the Hamlet/doubt/second-guessing that is one of my greatest weaknesses and flaws has to shut up and either sit in a corner or throw itself wholeheartedly into this absolute moment of making perfect circle with the feet here, then hurling the whole body into a slow dance on the pedals there to reach that climb with the knowledge that you cannot stop until you reach the top.
I realized I missed the mad-scientist/beater fixed-gear bikes as well, so first I picked up a sad, scarred '71 Gitane TdF and pieced it together for a family vacation bike. It became THE go-to early morning ride bike, because it was the perfect blend of responsiveness, speediness and good road manners. It's a treasured keeper because it's just so fiercely direct. I could say it's the metric-gauge 531 tubing or the geometry that is very close to traditonal road-fixed angles - 73 head, 72 degree seat tube, where many British road fixed frames were 73/71 - but in the end it's just how everything lines up into planes and turns the world into geometry and geography and I just have to deal with what is.
A few years back I realized I really missed my old Raleigh and started looking for a Competition at a price I could stand. This one is borderline cheating, as it's got four gear choices - but there is no shifting on the fly, I have to dismount and move the chain by hand. Running 42/44T chainrings, a Surly Dingle 17/19T fixed cog set and a White Industries 20/22T so I have 70-in pavement and 60-in gravel fixed gears and 60 and 51-in freewheel choices for general or light singletrack use.
