Ha Jim, that's what my father said about my Auntie, his sister-in-law. "They all say they're descended from kings!"
Sadly I have no idea where exactly my mother's Irish family were born, except it was either in or near Cork. My sister was told, as you say, that many records were destroyed and it's not at all easy to trace an Irish family's roots. Also, they had a very common name (think Murphy, just as universal as that)
I didn't realise they've done a remake of Roots Jim. Must give it a look!
In a mad way, my sis and I were quite disappointed that there were no skeletons in our family cupboard on my father's side. We'd have been really delighted to have had a couple of sheep-stealers, or deportations, some colourful miscreants and so on. They seem to have been a boringly respectable lot. Perhaps being at sea most of the time gave them little opportunity to get up to mischief.
I'd love to get a DNA test to see just what blood runs in my veins. I saw recently that most white people have about 2% Neanderthal in them. My husband didn't stop laughing for days when he heard that!