If somebody would have asked me at the beginning of January, how many flat tires I usually have per year, I would honestly have said "none". Now, times have changed, and this number has increased rapidly. Today I repaired my 7th puncture for this year -- I had 3 on the back wheel and 4 on the front wheel. On the back wheel I have a new inner tube now and never had problems ever since. And I will also change the inner tube of the front wheel tonight.
Some people say that if you have puncture once, you're very likely to have more. It's a kind of conservation law -- the series of punctures will continue. I don't believe in that. But I believe in fatigue of material. The last three punctures on the front wheel I all had inside, and they were quite big (today's puncture was nearly 1cm). My inner tube has problems with the rim as far as I can tell, as it got too brittle over the years.
Hopefully, after changing the inner tube on the front wheel, this series of punctures will stop for a while. Ok, I got a little bit angry when I walked out of the university on these evenings, just wanted to get home and had yet another flat tire, but it also has some positive sides: By now I'm an expert in repairing punctures ;-). I'm pretty fast and don't cover myself in dirt (except the hands).
In case you never repaired a flat tire, don't worry -- it is very easy. Almost every repair kid includes instructions, and many can be found in the internet, e.g. How to mend a puncture (which includes the very interesting "art of cycle maintenance"), The easy way to repair a puncture and Patschen picken (in German).
Well, so by now, on average, I have about 1 puncture/year . How many do you have? Can anyone beat my 7 flat tires for this year? I just hope I won't...