The Celts did not originally come from Ireland.
That is correct! They came from a Pub! They just can’t remember which Pub it was!
Doesn’t matter.
Wherever you go around the world you’ll find an Irish Pub
https://www.youtube.com/watch?v=bp3UsU5pQT8
Recent DNA analysis tends to show that the Celts did not contribute as much of their DNA to Ireland as originally believed. The Irish are from an older, isolated stock primarily, which explains a lot.
The Celts did have a large impact as far as technology and art however. Sort of like teaching a monkey to dance.