[Mediterraneo10]

> where on earth is it the norm to be living with your parents until you're in your 30s?

The south of Europe. Spain is probably the most outstanding country in this regard.

[rogy]

And increasingly common in the UK

[wyclif]

Yes. It's much more expensive now to get one's own flat or share it with roommates in, say, London than it has been in the recent past. And it's only going to get worse.

[wyclif]

Also southeast Asia! In the Philippines, for instance, it's quite common for both women and men to live with their parents until they get married.