Anyone remember the scenes in the main game of FFVII where some dialogue would suddenly appear and tell Cloud important things or just little chats every now and again?

Examples: In the first Mako reactor before Cloud sets the bomb, he hears someone say "Watch out! This isn't a normal reactor!" Or when he's in Junon, sleeping in one of the beds, the voice would say "Haven't slept in a bed like this in a long time." The last example I remember is when Cloud meets Reno in Aeris' Church, and the voice says something along the lines of "You remember him" or "You know him". I forget what was said exactly.

Anyway, does anyone else think that it was Zack speaking to him? There was no voice acting in the game, and no name given in the dialogue box when it would happen, but I think it may have been him.