3 Flats so far this year. 2 are my own doing. I keep screwing down the nut on the valve stem each time I check/pump the tire before rides. Twice the valve stem has torn from the tube. I shouldn't be so obsessive about screwing the nut down tight! Are they even needed?

3rd flat was on a metric century ride. I got dropped from the group I was riding with so I was just in a zone riding. Rode right past the rest area and got my flat a few mile down the road. While I was fixing my flat the group came by...they had been waiting for me at the rest stop.