In our country, one must go to the government "Office of Genius Certification." There is a lot of paperwork, testimony, signed affidavits, and a large fee involved. At the end of this one has the opportunity to join the ranks of certified geniuses. ***By the way, I LOVE this question!

But why 5%? Why not 10%. I didn't see any word like 5%.

A certified genius is someone whose intelligence has been formally tested and found to be in the top 5% of the population.