Absolutely YES! You seem to come from an extremely sheltered historical background.
You are quoting the British version of Celtic history, a narrow and navel gazing perspective. You have to go the continent to get the whole story. The Celts didn't originate in Britain. Maybe you think The Celts, a pop group also are bastions of Celtic history??? Please locate a GOOD comprehensive book on the Celts, not some British screed, and find out what really happened.
They didn't originate in the Caucasus in 610 BC, either.