Absolutely true.
Neither is the ability to perform physically demanding tasks an automatic consequence of youth. We're talking about expected values, not guarantees.
And I would certainly agree that someone who doesn't expect their career to increase their earning power over time would have a completely different expected-value calculation around impromptublue's suggestion than someone who does.
This is a repository for major, life-altering mistakes that you or others have made. Detailed accounts of specific mistakes are welcome, and so are mentions of general classes of mistakes that people often make. If similar repositories already exist (inside or outside of LW), links are greatly appreciated.
The purpose of this repository is to collect information about serious misjudgements and mistakes in order to help people avoid similar mistakes. (I am posting this repository because I'm trying to conduct a premortem on my life and figure out what catastrophic risks may screw me over in the near or far future.)