It's coming from housing prices in London and SF. Also energy prices in the UK the last few years grew considerably. I agree it's a lot of money, but given how much it costs to buy a house or an apartment in London and SF I'd say it's not that much if you want to retire early. I used London and SF in these examples because it's hard to find jobs with that much compensation outside them. And this is all without considering kids. You'll probably want them to have a good education and not struggle all their life from student loan debt so you better save some of your income for them.