My wife and I were into the second day of our ride across the U.S. when we stopped in a town for a break. I was looking at my bike and realized that I forgot my frame pump. It wasn't near as bad as the OP's predicament, because we had stopped in front of a bike shop

On a tour last summer I lost my wedding ring. My ring was always a little loose, but losing 5 more pounds on the tour made the ring loose enough to come off when I removed my gloves. I did not realize that it was missing until we stopped for the day. We think I lost it at the small rest area about 30 hilly miles back where we ate lunch.

On a tour a few years ago my wife and I were about 3 miles out of the town we had stopped at for lunch when she realized she had left her bar bag containing all her valuables (wallet,camera, passport, etc) sitting on a utility box, where we had parked our bikes. It was downhill back into town; and I turned and raced back, even passing a car on the way. As I approached the outskirts of town, I saw three cyclist we had met earlier at lunch heading toward me at a really fast pace for uphill riding. When we drew abreast they yelled and we all stopped. One of the fellows triumphantly held up my wife's yellow bar bag. Thankfully, I turned around and headed up the hill for the second time.