Ha ha ha ha ha
I used to think the same, OP.
The key is to be prepared. My experience is of being welcomed with open arms by nearly all the other parents in his class, but there were so many invitations to come over to play and have coffee etc etc when I was used to doing my own thing all the time, and found those sort of things highly stressful, that I had to tell people quite early on that it was lovely of them to ask but I just was not very good at social stuff and had too much to do.
Mainly people understood in the end as I am pretty good at the twice a day chatter, as long as that's where it stops iyswim...they know I really like them, and they like me I think, so it's worked out.
I just don't join in the social calendar outside school, and most people do.
I've fallen foul of various gossip-related disasters and also probably managed to get a lot of things entirely wrong, and sometimes it feels like being at school again myself, however much I want to avoid it, but the thing is when you've got to wait in the playground for 10-15 minutes every day at pick up, it's really hard not to talk to anyone, unless you're either foreign without much English or you keep your head RIGHT down and refuse to make eye contact with anyone at all, in which case a lot of people do get the message but maybe think you're a bit odd
(that's not what I do but some others do)
It depends how you are socially in general I think...I'm rubbish so it was never going to be straightforward, because it does drag you in and it isn't something you can easily avoid. If you have the skills and detachment necessary then you'll be alright.