[goldenchrome]

Since this is HN I'm guessing they work in tech, where 300k salaries (pre-tax) are common. Tax and SV living expenses use most of that, but you can still save a lot. You can save way more if you've got a high earning spouse.

The other key thing is investing in the stock market, specifically index funds which have a historical real return rate of 7%. Folks who invested since 2008 got way higher returns from a phenomenal bull run, but let's assume a more "conservative" 7% return.

Save 100k a year with 7% returns for 15 years and you have 2.5mil.

The flaw in that modeling is that your earnings typically peak later in your career, so OP may have made a lot of their money in the last few years from being a high level employee making 500k+ a year.