I thought Norway had a union with Denmark? gah! all those scandinavian countries sleeping with each other!
It is Norway was "born" when it got out of the union with sweden. So we call it out birthday ;P
Isn't 17 May when the king signed the new constitution (1814) rather than independence, I thought after 17 may you were still in a personal union with Sweden (rather than our bitches!) Seeing as you were declared an independent nation in 1905