Well, I never completely disowned my parents and relatives, but wasn't far off that at one time.
I hated the way my parents would try to lay this notion onto me that I had some kind of duty to associate with family members.....particularly one of my grandmothers who was downright rude to me - I'd grown my hair a bit beyond the "acceptable" short back and sides of the era, and she said that if she'd seen me in the street looking like that, she wouldn't have spoken to me. So I had nothing to do with her after that. I was a teenager at the time and I was rather arrogant anyway, feeling that young people were great and older ones were mostly wrong-minded and boring. Really I just treated them like I'd have treated anybody else, i.e. on their own merits as I saw them at the time. So once I'd left home, I just kept in touch with the few family members who I got on with, plus the occasional duty visit to my parents and sister. I mellowed to some extent as I got older.
There was also a huge problem with my mum who had always been very overbearing and pugnacious with me, and my dad wasn't all that liberal-minded either, so I pretty much had to remove them from my life in order to grow up......if they'd known about half the things I was getting up to, they'd have worried themselves sick and put a lot of pressure on me to toe the line, and I wasn't having any of that. I kept up the visits and became closer to them again once I'd established myself as a person in my own right, but they never knew much at all about my adult life.
To put this into context, I was a teenager in the late 1960s and early 1970s, which was a time of massive youth rebellion and questioning of old-school values. A lot of my generation really thought we were going to sweep all the crap away and replace it with our own Utopia, but ultimately we weren't able to change things very much.