When it comes to memory, humans may not be the only ones reliving the past.

Recent studies suggest that cuttlefish and octopuses - those soft-bodied marine brainiacs - might possess a form of episodic memory: the ability to recall specific events from their own lives. That's the same kind of memory we use to remember a birthday party or what we had for lunch yesterday.

In one experiment, cuttlefish were trained to expect different foods at different locations and times. Not only did they remember what they ate, but where and when they had it - days later. Octopuses, too, show signs of individual personalities and can remember solutions to puzzles they've seen only once. Their nervous systems are wildly different from ours, yet they solve problems, remember strategies, and possibly even dream.