I'll take the risk and say that you might find yourself changing your approach as you near your 60s.

When I was 30, I couldn't fathom the idea of ever wanting to retire. I loved what I was doing and was happy I was getting paid to do something I loved.

Over time, I realized that "retirement" doesn't have to mean actually stopping any work and just sitting in front of the TV all day, or playing golf or whatever all the time.

The critical part is to reach a financial point where you can cover your lifestyle costs without ever having to earn another penny. Once you get there, you can pick and choose what you want to work on and who you want to do it with, never having to consider if and how much it'll pay.

Whether you reach that point at 30, 40, 50, or 60, it doesn't mean you stop working. It means you have complete freedom in structuring your life at the micro level (i.e., what will I do today) and the macro level (i.e., what will give the rest of my life the most meaning).