luck, mostly.

i did a phd which took until i was 26, after which i was at effectively a zero bank balance, give or take a couple of hundred quid into the student overdraft. but i got to move in with a friend who had a death in the family and they needed to effectively squat the house so the insurance was valid, which i managed for a bit until i fell into a postdoc position where I was earning £35k a year but most of my friends were still students

so my expenses were effectively the same as when I was on my phd stipend of 14k, whenever we ate out it was still piss cheap, no car or anything etc etc. still traveled, but a big part of the luck i had was that a lot of my holidays wound up being part funded by work - i'd almost certainly have traveled less without that, but on the face of it that's probably saved me 8-10k. Doing that for years meant I had a little bit of a stash built up, so when I finally found a open ended contract rather than something a year long, i could just about scrape together enough to buy around here. I also got lucky that I bought in mid 2019, if I'd been a year later I'd have been fucked as all the London folks decided they wanted to move up here lol.

in terms of family support, I have moved home twice in the last decade for a month or two while being between things, which is huge. them providing me a space to "fail" into and be able to chase the fancy jobs that had all the perks rather than "oh shit I need to make rent, time to go stack shelves in Tesco" is what got me even close to buying a place. They wound up added some money to my deposit too so I could afford a place with a spare room for them to use, but (without wanting to belittle the fact that they absolutely supported me there) that was less impactful than the guaranteed roof over my head they could give, the direct financial support was "only" the difference between 2 and 3 bedrooms, rather than buying or not.