In terms of probability, 4 punctures in 3 rides usually points to something still embedded in a tyre, or pinch punctures from the tyre levers.
Without wishing to teach anyone to suck eggs, it's worth emphasising the benefit of regular weekly tyre pressure checks. A track pump with a pressure gauge is the kit you want. With high pressure tyres it's very hard to get the correct pressure. Personally, I held off from buying a track pump for years. I was too tight! In hindsight, I realise that was a mistake.
There's also the question of riding style, and picking a line that's likely to be free from road debris. If you can, keep in the tracks of the cars, and don't ride too close to the edge of the road. Similarly, I would sweep the front wheel with the palm of my glove if I accidentally went over glass or similar.
For commuting in London I used Continental GP3000's during the winters, then Conti GP4000's, and in summer Veloflex Masters. I used to average about one puncture per year commuting and training, and several per year racing. Given the huge difference in mileage, I suspect that racing punctures occurred precisely because one tends to ride across everything on the road in a race, rather than ride around.
Recently, I used Continental Grand Prix 4 Season with DuraSkin for one year training in Indonesia on terrible roads, where the surface was often entirely broken and there was every type of debris. No punctures. As they say, YMMV!