My dm was overprotective but not to an extreme.
There were things that did effect me socially.
One being at primary school most of the children (in each year joined up in the evening and went round in a group into each other's houses and then drifted home as it got dark/bedtime. I was rarely allowed, and even if I was it was on a "well you can go to X's house, but no others" so I'd go, then they'd want to move on and I'd have to go home.
It meant that socially the rest of my peers spent all evening together so naturally I was the outsider because I didn't have that interaction. I'd find jokes had been made, ideas planned etc that I just didn't know about. I wasn't too bad at working round it, and either pretending someone had already told me or getting them to tell me and being very flatteringly impressed.
Tbf I think if we'd had mobile phones, she would probably have been more lax.
The other one was no going in other parent's cars. I'm talking about by arrangement, not taking an unexpected lift, which is fair enough. That meant she either volunteered to do the driving (eg to a sports' match) or I was taken on my own. So I'd always be the one in the front separated from the giggles in the back, or arriving separately having missed out on the bonding on the way there.
She also would give us a lift rather than have us take the bus. Which my friends at secondary often thought was great, but did mean could only go if she was available to take me. Actually I think I'd have enjoyed sometimes being allowed to bus.
I think it effected me in some ways less than my siblings in the long run. However I don't think either of my siblings were particularly affected at the time because they weren't very social and I don't think particularly wanted to go off with their year group or go to things in others' cars. They didn't want to do stuff that I did. But I have noticed with both of them that they don't pick up social things very well. Would they have gone out and learnt if dm hadn't been overprotective? Don't know.
How has it changed me? I still feel a grain of naughtiness when I'm out alone after dark 
as that was definitely a no go. I've made an effort with my children not to let my worry stop them doing things unless it clearly is unreasonable. I do very easily feel on the outside of a group, but I think that's personality rather than anything else.