the Celts dont have a creation myth. or none that i've been able to find anyway. this is odd, as the creation myth usualy sets the standard for all the myths that come after. theres plenty of attention given to the celtic gods powers and roles, but little to no explenation of where they came from. as well as the bigger questions of who created the universe, mankind, etc.
i've run into this a few other places, but the celts made it stand out more as i have some heritage from that area (along with every other anglo-saxon....heh)