I'm not so sure Carlsen's memory is all that special. He often plays non-critical lines. He seems to stay away from testing his opponents' memory rather than challenging them head-on. 

I'm not saying Carlsen has a bad memory, just that if his memory was markedly better than other top GMs, his openings would be a bit different.

So far, one of the most impressive aspects of his game is how he can squeeze out wins from seemingly dead positions against some of the best technicians in the game.

All three plus maybe more?