Jim, all very interesting, I agree. But if you do a search on this site, you will see that opinions vary alot regarding what's needed for a cruising budget--from minimalist at 10K per year to more than 5 times that, and it will vary with number of children as well.
Most people would have a hard time coming up with your suggested figures of 500K cruising kitty and another 500K retirement fund. Obviously the more the better, but one can end up saving forever and not getting off the dock.
The hard part is finding the right balance between having enough money to be reasonably secure and not postponing so long that health problems or other life events overtake the plans.