Maybe you just have a cruddy pump. I have a Topeak Road Morph, and it's quite good.
You probably need to carry a pump anyway; if you have more flats in a day than you have CO2 carts, you're walking. Unlikely, but it happens. I once had 5 flats in one day, and it was NOT because I didn't get the sharp thing out of my tire, I was just really unlucky.