That is an amusing hypothesis but difficult to prove. Truth is more interesting. The ancient Celts originated, most likely, from around the area of the old Euxene Lake which became flooded from the Aegean Sea in a break through an isthmus circa 7,500 years ago. Massive flooding caused an exodus of peoples away from what would become known in the ancient world as the New Euxene Sea (the Black Sea to us).
This ancient flood perhaps explains why so many peoples in the Europe-Asian landmass have myths involving a cataclysmic flood.
There are several flood myths. One takes place in the Indus Valley, and has a boat that ended up stranded in the Himilayas near the disputed Kashmir/Jammu and Alqaida/madrassan training camps.