It's quite simple. I did ok when I was younger and save up a bit and sold a very small business I cofounder, I'm now starting again as a junior doctor. My base pay is 30k (ST1 trust grade). I get 12k banding for working nights evening and weekends, 2k london allowance = 44k pre tax so take home is 2.5k after pension, student loan (I did one year in the uk back in 2000) and any other bits that come out.
My house is sorted, I don't need to save from that so I'm happy enough to just spend my income farting around in london on weekends. I'm not working for the money I do it because it's something I want to do and it will lead to a decent stabl job in the future. At the moment I get a lot of satisfaction from what I do so I have not plans to change.
I spend so much time at work excluding the cars I could live off what I make if I needed to.