I just heard from a distant Irish cousin. How distant? We're both descendants of a pair of my great-great-great grandparents. That's pretty distant!
Bear in mind, you have 2 sets of grandparents, 4 sets of great-grandparents, 8 sets of great-great grandparents, and 16 sets of great-great-great grandparents - unless you've got some cousin marriages in the family tree, and the math suggests we all do, somewhere back up the line.
Of course, if you trace it back, we're all related,
but figuring out just how is complicated.