Here in the southwest thorn-resistent tubes and/or slime or airloc are pretty much required if you're gonna ride a bike. 1 of my road bikes has Kevlar tires, regular tubes and Air-Loc in them, my other road bike has regular tires, TR tubes and Slime. I would rather have the slight weight added to my tires and not have flats than spend time on the side of the road! Air-Loc is the "new" slime and is lighter in weight and doesn't congeal like Slime has a tendancy to do. Oh..and I have Air-Loc And TR tubes on my mountain bike. (we have these Reaaaalllllyyy nasty thorns out here called goats head {picture a real goats head....you got it} that will take out Anything it touches!)
One suggestion would be next time you change a tube - run your tire lever around the inside of your tire and make sure you don't have something sticking through that could potentially flatten the new tube. That might help.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand, strawberries in the other, body thoroughly used up, totally worn out and screaming: "Yeah Baby! What a Ride!"