I find it sad when people say that they wouldn't know what to do with themselves if they retired early and shows a compete lack of imagination. I took early retirement just before I was fifty and have never been bored since that time.
Again to believe that stopping working means that all learning stops, is again extremely short-sighted. Today...more than any other time, learning opportunities abound, given the plethora of these to be found on the internet. A friend of mine in my writers' group who is in his eighties, added to his original university degree by taking an honours degree in creative writing and then immediately went on to take a Law degree which will finish in a years time. Life should be much, much more than just work, and it's important in my view to have an inner life which can sustain you when your working life comes to an end.