What do I think echoes are? [he frowns a little into the camera and shrugs.] Pieces of something else, another past or another person but someone who is somewhat like me.

What prompts them depends. Sometimes running into weird things brings a piece out. Sometimes I get the feeling that something has happened before. The strangest thing was a water pistol fight, the most mundane was getting stuck on a beach.

I'm not sure of the number but there are a few of them.