What would offend a Celt?

[Cyclops]

Does speaking a Celtic language make one a Celt? As opposed to utilising a Haltstatt or La Tene material culture.

... so no Jurassic Park for you.....

Now I'm upset. Does that mean I'm a celt?

...incidentally, is Keltoi Greek for the people around Massalia or the people of Pannonia?....

A quick wiki search (for what thats worth) says the first mentions put the Keltoi in W or SW Germany and at the root of the Danube. So I think Bavaria/Switzerland is intended.

... including Attila the Hun, probably...

I knew he was a brother! Drank so hard on his wedding night his head popped before he could get to the bride! Now thats a true Celt.