I think initials should be accepted when using them in brief for the directions (E for East, W for West, N for North, S for South). I answered N Korea for the picture of Kim, it's obvious(?) meaning North...can't we get that changed?
The Mesolithic (Middle Stone Age) follows the Paleolithic (Old Stone Age). The Neolithic (New Stone Age) is the third/last part of the Stone Age in general.
Thinking of the planets helps, I often have it the other way around and cant think of poseidon (besides neptune I weirdly enough cán think of triton, but poseidon often stays out of my grasp)