Ten years ago today, I bought my first iPhone. My experience activating and setting up my first iPhone is here. My observations after three months with the first iPhone are here.
In the ensuing 10 years, I am frankly not sure how many different iPhones I have had. My guess is probably seven [original, 3G, 4, 4S, 5, 6 and 7]. This works out to about 18 months an iPhone. I wish I had I kept track of all the different models. I got an iPhone 4 in June of 2010. I got an iPhone 4s in October of 2011.
I am currently carrying an iPhone 7 that I got September 23, 2016 when my previous model was having problems with the lightning connector.