Once upon a time I though I was at least half Irish. Ancestry DNA cuts that to 41% with only 38% from Dad, who turns out to also be German and Scottish.
It doesn't help that names like James, Timothy, Bridget, and Mary Ryan are as common as bottles of Guinness.
Bottom line:
18 degrees to Jonathan Swift. Two each at 19 and 20 degrees. No cousins closer than 10th, 3 times removed (Edmund/John Synge).