I passed the 100 shaves mark sometime recently. The learning curve is rather interesting. I made a substantial amount of noticeable progress in the first 30 or so shaves; each shave had less razor burn than the shave before, and took less time as I learned how my face works and how to shave each area. By this point, my shaves were acceptable, but there was always some irritation somewhere.
Over the next 50-60 shaves, progress was less noticeable, but irritation-free days began happening more frequently, and the time it took to shave dropped substantially, from an hour to shower and shave to 35-40 minutes. The gain is in shaving time, as my showering technique hasn't changed. :) My two problem areas still presented a challenge, however, and were usually the location of any irritation/razor burn.
Sometime recently, I've managed to consistently shave without any irritation or razor burn, day in, day out. It made me curious to check how long it has been, and it turned out to be right around the 100 shave mark. It's been 112 days, and I haven't missed too many days in there. My observation is that while there's nothing particularly special about 100 except that it's a round number, and everyone's learning curve will be different, it does take some time to be able to manage all aspects of a shave without having to be thinking about everything...pressure, angle, how to shave each patch of skin, where to stretch, etc.
The time is clearly what it takes to develop muscle memory and learn from mistakes and successes. I think it takes the right amount of stubbornness; you have to be stubborn enough to ride through the rough beginning when you've got razor burn and look like a teenager after his first shave, but you also have to be flexible and try new things each time, repeating what worked and altering what didn't. Stubbornly sticking to the same method in an attempt to make it work will probably fail.
Just my observations at this point in my journey.