I had one of my runners make a huge score (2 million nuyen) and we talked about retiring the runner. The player brought up an interesting point. So...how can an elf, who may have a 200 plus year life span, retire? Too many things can happen.
1) Even buying a permanent lifestyle, read the books. It even alludes to stock crashes, the past coming back to haunt the runner and ruining the SIN it takes to maintain the lifestyle, etc.
2) Even in real life, catastrophe happens. Take WW2. My grandfather owned an insurance company in the Netherlands. Hitler ruined that.
So how can you feasibly retire if the rest of your life is an unknown? Especially since you don't know how long "the rest of your life" is!