Does Sir Quackers have amnesia?

It really is, actually. One of the nicest things about amnesia as a plot device is that it allows a new character to be a blank slate and to discover facts about their past at the same time the audience does, both of which are fantastic things for first-person stories like video games. In fantasy stories, that can also help justify a large amount of exposition, allowing other characters to fill the amnesiac character in on things that should be common knowledge to most characters in the story but are less familiar to the reader/watcher. In a mystery story, it can deepen the mystery by resetting the basic knowledge of a protagonist or witness, having them start from square one even if they themselves had an integral role in the mystery they're investigating. It also can even make for an interesting soap-operatic plot twist late in a story, since it can allow an established character to take a look at their past identity from another point of view and perhaps gain new insight into their own actions, character traits, and past experiences.

All that's not to say that it's not occasionally used for lazy writing or treated completely unrealistically. But there's a reason it's been a staple of fiction for so long.

Oh yeah, it's super useful.  I used it this one time and...uh...

...

Hm.  I...don't remember what happened after that...

Bionicle in a nutshell.

I thought this was gonna be an entry about how you suddenly have amnesia and need our help to restore your memory. I've never been more disappointed in my life.

I thought this was gonna be an entry about how you suddenly have amnesia and need our help to restore your memory. I've never been more disappointed in my life.

if I had amnesia and forgot about this website I probably wouldn't come back tbh

Wait.

So if amnesia is a good writing tool... What about other issues, like emaciation?

"Tahu woke up one morning to find himself fully emaciated. What the Karzahni." (also he's alive because Bionicle physicsssssssss)