And now my foreshadowing about Mega Man losing his memory comes to fruition.
My reasoning was that since this Mega Man, the Mega Man of the past, doesn't have any memory at all, if our Mega Man, the Mega Man of the present, isn't being protected from the changes to the timeline, then he would be slowly turning into this Mega Man, and he would slowly be losing his memory. See, it sorta makes sense.
But why the unnecessary plot complication? Well, I realized that if Mega Man already knew everything about the various Robot Masters from the second game, the storyline would probably be pretty boring and repetitive as he works his way through them. Besides, I wouldn't be able to have any of the fun introductions I'm so fond of.
By the way, "chronitons" are also particles supposedly linked to time, but they're much more fictional than "tachyons". I suppose you could argue that if everything can be broken down into discrete quantum units, then time could be composed of particles you might call chronitons. At least they sound better than "temporons" or something.