retiring with a shitload means you worked too long.
I see it differently. A shitload means that you don't have to worry about money at all in retirement and you can do whatever you want to. If you have just enough money, then you need to be more cautious. A shitload is the way to go.
It is probably the difference of working an extra 4-5 years on average.
Simple Example: $2MM is just enough. You can withdraw 4% annually ($80k), live a decent life, and probably not run out of money, but you are limited to $80k annually.
However, if you work an additional 5 years and invest an additional $15k annually, you will have just over $3MM. Withdrawing the same 4% gives you $120,000 annually and you will probably not run out of money.
(this is all just to show a simple example. there are plenty of holes in this and it is not reflective of
my more in depth plan)
EDIT: Which entails windfalls and such.