What caused your recent flat? Examine the tube to find out. Is the hole at the stem? Defect, damaged by pumping, or damaged by riding with too little air pressure. Is the puncture on the outside (tire side)? Probably punctured by a road hazard. Is the hole on the rim side? Rim strip or tape isn't protecting your tube from spoke heads & nipples (single wall rim) or spoke holes (double wall rim).

As for the number of flats you've gotten from road hazards... Sounds like you should consider investing in tires with a puncture-resistant belt made of Kevlar or similar fabrics. A few examples are the Panaracer Pasela PT, Panaracer T-Serv, Continental Gatorskin, Schwalbe Marathon, and Specialized Armadillo.