Civilization "doesn't want anything to do with me right now"?

So in Civilization V, I'm playing as Polynesia on an archipelago map. The first Civilization I come across is Greece, on an adjacent chain of islands some 20 hexes away from mine. About 10 turns after I meet them, they suddenly become hostile towards me and start egging me on about how weak my military is and how I should watch my back. When I check the details of our diplomacy, the only thing that appears (in red) is "they don't want anything to do with us right now".

I had never seen this before, and I can't imagine what would trigger it. Moreover, they didn't covet my land, as they hadn't even seen it (this was only like, the 20th something turn, so they couldn't even sail over to it if they wanted to). Whatever it is, it must be pretty serious if it alone can trigger open hostility that quickly. Does anyone know what this means, and what triggers it?

Solution 1:

If you look in the demographics (button near the top right) you can see who has the weakest and strongest military, production, etc. The AI seems to keep a close eye on this.

Generally if you have a much weaker military than an adjacent AI civilization they will be all too happy to attack you.

Also, Greece always has a very strong military at the start of the game since they get both of their special units at the beginning. They are looking for an early fight.

To summarize what happened to you, Greece went with a full military start and your military did not compare to theirs. Because of that they don't respect your civilization and want to attack it.