My mother was ridiculously overprotective. I wasn't allowed to walk to school alone until I was in sixth form. I couldn't go into town with my friends on a Saturday afternoon until I was 17 and then only for two hours. When my friends started turning 18, if they invited me to their parties I was allowed to go for the start time and I had to leave an hour later. That way my mother could say I'd shown my face and that she'd allowed me to go when I complained that I wasn't allowed to do anything. She would wait outside the venue for me for the full hour after walking me there, and then she'd walk me home (this was only for places like our local community centre hall or someone's house if parents were present, I wasn't allowed to go to parties in clubs or anything). There was one venue in particular that lots of my friends had their 18th parties at and she would stand outside the main window and look in for the whole hour. In the end I was so embarrassed I stopped going, and the invitations dried up anyway. I was bullied for years at school for being a weirdo.
I wasn't allowed to go to the cinema with friends until I was 17 and she did the waiting outside thing for the whole film - at one point I went to the toilet and I could hear her talking to my brother outside (old fashioned local cinema with windows that opened onto the street). She often used to bring my younger brother with her to wait with her 'for company'. I wasn't allowed on school trips, to stay in for lunch at school for clubs, no school discos as I got older, no sleepovers.
Then she got a boyfriend and literally overnight my brother (three years younger than me) and I were left to our own devices. To say we made up for lost time is an understatement. We went from having our every move monitored to my mother not giving the tiniest shit about what we got up to. I went off the rails massively. I ended up with a drink problem, and got myself into some awful and very dangerous situations. I had had no guidance whatsoever as to how to 'adult'. Some of the things that happened to me still have repercussions decades later. It took me years to get my life on a slightly even keel.
I had to be so, so careful when DD was younger. So many times I had to stop myself from being overprotective myself, or going too far the other way to prove to myself I wasn't like my mother. Thankfully I had DH to guide me (his upbringing had its issues but his parents were never overprotective and were quite healthy in that respect). DD has turned out fine and there haven't been any issues but my god it was hard.
Funnily enough, when I was much older my mother completely denied she had been overprotective at all and claimed that I was a juvenile delinquent who she couldn't control, and all my issues were my own fault. She was so convincing that sometimes I doubted my own version of events. But other people I knew from back then, and relatives too, reminded me of what she was really like.