Having babies before you have finished all the formal education you want to get.
On the other hand, waiting until you have your Ph. D. to begin breeding carries other risks. In this case, one should find an advisor that understands the stress maternity involves. It's entirely possible in some schools and disciplines to be practically done with classwork after the second year of study, and in some places it's possible to take a semester of unpaid leave without forfeiting the program.
Just freeze your eggs. Far cheaper than having children during the crucial early-career-building phase of your life.
It honestly blows my mind that people rearrange their whole lives around having kids early instead of doing this.
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.)