One of those days - Part II

Later this afternoon, I fix the back tire for the fourth time with my second spare tube (the one I thought that I had lost). It works perfectly. I ride around the neighborhood for awhile and everything is fine!

Then, I go to the bike store. I ask to buy some new tubes to replace the one's that I used today. The guy behind the counter replies, "Oh those types of tubes are really light, but they get lots of flats!" Now he tells me! I now have the heavy duty tubes ...