I'm from the west of Scotland and there's a massive Irish influence here, most notably on the Scots language and place names. Most people probably have Irish DNA. So it amazes me how different the Irish slang is from Scottish slang. The only words we use are "gobshite", "fucked" and "rat arsed". Bollocks has morphed into bawbags here. Try explaining "Ya bawbag" to an Asian visitor.
When I visited Dublin years ago I saw old men wearing Fcek t-shirts. I like the Irish sense of humour.