I am Irish living in Ireland. My DH is British, he is an immigrant who grew up in London but had lived for 20 years in Ireland when I met him.
I discovered mumsnet about 8 years ago when I took on a sort of stepmum role and was flabbergasted at some of the stories, attitudes and opinions.
I still found the site extremely helpful, often giving me clarity on situations which would cause me a lot of angst.
However when I talk to friends and family members living in the UK I realise that a lot is to do with cultural differences.
It's amazing given how close geographically we are.
Attitudes to money, marriage, divorce, wedding gifts, abortion, house purchases, communication with friends are so far from anything I've seen in my circles.
To give my pov; (these are all generalisations) we get married later, we stay married, we don't consider abortion unless it's very particular circumstances, we are indirect about money "I'll get this one, you can get the next one (but it is LAW you only accept if you are buying back)" and sending bank details for a small amount would be horrifyingly rude, you only attend a wedding with a card containing at least 100 euro pp, you usually get married in your mid thirties, your kids are mainly all with the one father, we hide behind humour until we know a person very well, we don't report benefit fraud, we laugh a lot more... That's just off the top of my head.
The other thing is that most Irish people know all about English Irish historical tensions but many English people are utterly oblivious.
YABU You're talking out of your ass
YANBU The differences are enormous
I'd love to hear some thoughts on this. In my line of work now I do a weekly call with my UK based team and I always notice subtle differences in attitude.