I didn't go to uni at 18 - at 20 I'd planned to move out because I had a secure full time job, then I stupidly changed jobs to a new place that was so bad I had to resign.
I ended up temping for 3 years, hoping for a permanent position. That meant I didn't have the regular income to even flatshare and had to stay with my parents even though we rowed a lot.
I still had boyfriends back (none were serious enough to move in with), went out and got drunk a lot, paid rent, bought my own food and cooked my own meals so I was quite independent anyway.
My parents split up when I'd just turned 23 and mum moved out; I applied for a nursing course at uni and stayed with my dad, working full time and saving money for a flatshare, until the course started age 24 - that's when I moved out for good.
It was a shame I couldn't leave home sooner because my dad and I didn't get on at all well, I felt I was in his way all the time and dreaded going home from work. Once my mum had left the house it was very much his home and he didn't like me cooking or doing anything outside my bedroom. The situation was very tense and escalated to him slamming a door on my hand.
Once I'd left home I repaired my relationships with both my parents and we got on a lot better not living together, now years later we're all good friends and I see them regularly.
I got to help out my mum a few years ago when she was between flats by letting her stay in my spare room for a few months which was nice actually.