Ok so here is the deal. I get a great person science, arts whatever and I'll sometimes save them to use them for a Golden Age. But I have had a situation where I had 4 great scientists, that I fortified to wait till I had enough to trigger a GA...when I finally have enough the golden age button is greyed out. I mouse over it and it says need 3 more to trigger golden age. In the city I can see 3-4 more so I have enough to run a GA but it wont give me an option. I should have screened it but I didnt. Why is this happening?