Given that, it was surprising when I walked over to my bike in the bike locker and noticed that my rear tire was flat. I removed the tube and checked for sharp objects inside and outside of the tire and found nothing. More alarming, I pumped up the tire and couldn't find the leak. I decided to replace the tube in case of a slow leak, and then pulled out my spare. The very new spare's lock ring was stuck on it - the threads were messed up, most likely in the manufacturing process. I couldn't get it off and if it was on, then I couldn't get the tube on the rim. I had a second spare ... for my wife's mixte, which uses Schrader values. By then a colleague came out for his bicycle and he couldn't budge the lock ring either. So I carried my panniers, which were mercifully light, except for the U lock and cables, and my bike, which is not mercifully light, to the nearest bike shop, only a quarter of a mile away. They checked the tube and with not much force, tore the valve off. They checked the spare tube, unjammed the lock ring on it and used that spare. The tire has held air since then. I very lucky that I was that close to someone with tools to remove the lock ring.
On the ride home, the spring on the Avid Shorty 4 rear brake jumped of the pin that holds it in place so my bike was suddenly very sluggish. I pulled the cable on the brake and rode to town, without a rear brake, for a toddler concert and dinner with my family and then on to my car near the preschool, where I parked it for the day. I have since checked the tire, fixed the spring on the rear brake, re-centered the brake (I so love this process on these otherwise good brakes), and restocked two new tubes in my saddle bag.
Given historical averages, I should have 4,000 miles before my next flat. But it's actually been 7,000 miles since my last flat. And the commuter has pretty sturdy tires, Panaracer T Serv Protec 700x32 commuters, which have been bomb proof and apparently still are. I had two flats on my road bike in its first year, on 700x23 Michelin Krylion tires. Both were side blowouts from glass that had me limping home with dollar bills holding in the bulge from the torn sidewall. I later had another flat on this same kind of tire. I have since switched to a 700x25 version of the same tire and have about 1600 miles on them, flat free. They have held up well. In any case, I'll carry two spares on the road bike as well and hope for another 7,000 miles before my next flat.