If you took out mortgage when interest rates were really low, it’s possible to have your own place and spend about that much per month if you live frugally (well at least until you need to remortgage in few years and rates might be much higher). If you are renting though I also finding it difficult to believe. I was spending around 1600 pounds per month and I was living very modest live, spending little and trying to save as much of my income as I could.

Well my rent is only £600/month which helps a lot. It's in a less popular neighbourhood, but it's still in Zone 2 with good transport links and it's very nice.

Do you live alone or with other people and you split the rent? How much do you pay for council tax and bills? 600 is very cheap in London.

There's zero chance they are living alone anywhere in London for £600, let alone zone 2.