I've created a number of spreadsheet scenarios for myself spanning the next 60 years (until I'm almost 90) and think I see what you're getting at as well. Given the buffer I plan on creating for myself, when I retire I will gaining significant amounts of interest money annually if I only pull what I need. Then my pension kicks in and I draw practically nothing from investments (maybe even draw none and actually add to investments!) and see the stache grow gigantic! So, when I'm 65 and have been retired for 20 years, with potentially ~25 more to go, and have 50x my annual expenses saved, why not buy an expensive sports car or donate a f@*k ton to charity, at say, 5x my annual expenses?
tl;dr: it's your money, save, spend, generally fuck about with it as you see fit.