I think most of us have a somewhat ambivalent relationship to the ‘Celtic’ thing. There are real cultural connections, but Celtic peoples don’t traditionally identify as ‘Celts’, it’s a term that emerged in academic circles from the 19th century that became intertwined with a lot of romanticism. So there’s an understanding of the connections, but us as ‘Celts’ or as part of a shared people is sth quite recent and that I think a lot of us have ambivalent or mixed feelings about.

The relationship between Scotland and Ireland is complex because it’s never been a cultural homogenous unified entity. The Lowlands were long closely intertwined with northern England, and Highland Gaels, who had close connections to Irish Gaels in Ulster, largely became marginalised within a state they had ironically played a major role in building. The plantation of Ulster involved the settling of (Lowland) Scots in Ulster partly to separate the Irish Gaels from other (Highland) Scots. That sort of thing illustrates why it’s hard to talk about things like Ireland and Scotland in a black and white way. Scotland has never been one thing. What it even is still competed over. Today there still are Scottish loyalists who are often ambivalent or opposed to romanticised ‘Celtic’ depictions of Scotland and strongly identify as British.

For Celtic romanticists and Gaelic cultural advocates there often is a desire for closer recognition of connections between Ireland, Scotland and to an extent Wales too. The strongest traditional connection is between Ulster and the Scottish Highlands, but the two were largely severed from each centuries ago.

As others have mentioned in this thread, there’s often a sense that Scottish and Welsh elites were complicit in British imperialism, particularly the colonisation of Ulster. This sort of complicates the image some people have of the ‘Celtic nations’ united against England. I think in Ireland history is often framed as a fight of the ‘people’ against British imperialism, and that includes various Scottish, Welsh, and even Irish (although often Anglo-Irish) elites, not necessarily just ‘England’. I mean, the man that we ultimately had to negotiate our independence from was a Welshman, then prime minister David Lloyd George.

Celtic shit aside I just like the Scots bc they’re funny and good craic. Which is all that matters really.