Well my family is from Central Scotland, that nation being the most Young-ridden in the United Kingdom. It's also pretty common in England, and Northern Ireland has it's fair share, mainly of Scots descent. There was a Young family in my home town a century ago who were immigrants from Prussia. Almost certainly they were originally called Jung, which is the German for "young", the pronunciation making it easy to be absorbed into the host language. No doubt there is no shortage of Youngs in the English-speaking world who were once called Jung, or the Dutch equivalent, Jong. I also met a Chinese called Young, though his name is usually written "Yung" in English. The meaning is "junior", e.g., John, son of John Smith might have become John Young to avoid confusion with Dad.