Probably the "things" the vast majority of human beings really want are the likes of peace, contentment, happiness.
From my perspective (as well as others I have known over the years), the aforementioned does not necessarily flow from acquiring a ton of material possessions.
Regardless, the question here is unusually framed as the bulk of material items are acquired over the course of one's lifetime and not typically immediately following retirement after having worked for a specific number of years (which is actually when a lot of people start getting rid of stuff they have acquired over the years).
