About a year and a half ago, I purchased my first fixed gear bike, at age 62. The bike is a blast. I shouldn't have waited as long as I did to ride fixed. I'm a little sorry I didn't go more old school with my choice of bike, too. (I do still have and ride my 1962 Follis, a French road bike.) The Langster is fine, though; it's lightweight and responsive and all the parts work.
I bought my bike while visiting my daughter in Manhattan (I'm from Los Angeles). This year, I shipped the bike back to NYC for another few glorious days of riding around the Big Apple.
While my main bikes are geared, I've put plenty of miles on my Langster, too. Having grown up in L.A., I have respect for traffic, but no particular fear of it. On the occasional Monday and Wednesday nights, I join a shop ride, and I find that on the mostly level ground we cover, I can keep up with the riders who are in their 20s. For me, a fast ride to downtown or the beach and back gives me a terrific workout.
Of course, when I look in the mirror, I think, "What happened!?!" Reflecting back on the sedentary lives of my parent and their friends and my relatives, I'm somewhat amazed I'm still riding at a fairly high level. Then again, I've never been especially sedentary, compared to lives my elders led. I may look my age (older, from too much time in the sun); on my bike, I still feel as if I'm 25.