Its different from someone to another, like you said. Its up to how you feel about it.
But f you start working and has the money to pay for an appartment and food, it think it is better to live by yourself. Of course, if your parents dont live in the mittle of nowhere, you can still live in the same city as they do, or somewhere close, so you can still see them often.
Personally, i will trun 21 this fall, and i live with my bf. When i was 17, i did an exchange year in the USA, then when i came back home, i went to college and as it was a bit more than 100 km away from my house, i rented a small room there. But i hated it as i was alone and all my friends were studying something else or somewhere else and werent in the same class as i was... i was with people 1 year younger than me, and i felt like they were somehow still very childish (yeah Taliesin, i know it sounds weird coming from me, so they had to be awful..). I
Then i met my bf and later i decided to move to Germany to live with him. It was probabily the best choice i ever did in my life...
In Belgium there are lots of peple who transforms old appartments into rooms for students, or universitiesthemselves have some buildings with rooms for students. So the students live with otehr students, i guess its a bit like a dormitory then... But generally the country is so small that you only have to travel max. 200km to get to your college, and go back to your parents every week end. So most of the students look for a real appartment when they start working, but at the same time ,they already have an idea how it is to live alone.
Actually, how old are you now (if you want to tell it)?
I have known someone who, at the age of 30, still lives with his parents, even though he has a girlfriend, has finished college for years and now works. At that point, it sounds kinda ridiculous...
EDIT\ and now that i dont live with my parents anymore, i think that we get along together much better than before. And i enjoy the time i spend with them when i come back home for a few days. No stupid quarrels with my dad anymore!