That she wouldn't do something that made you upset doesn't mean she can't do something that would make you upset. It's a mere matter of if she would realize that it would make you upset or not, if she doesn't she may do it, thinking that you wouldn't take it too seriously or get upset.
[Yoh doesn't deny her optimism or her words. But the human mind is very narrowed and it's easy for it to miss things, specially regarding others' feelings.]
But if that's not the case and it's not a prank. Then it means that there's a problem indeed. You could check in with your neighbors or people whom you both know to see what they remember. If they remember the other person living with you two then it's most likely that indeed something has happened to your memory after all. But if they don't then the problem will be in their memories.
[But both options are just equally bad. Either Madoka would get upset because her memories are wrong or she would have to decide what to do regarding the other two. Confront them and upset them because they are probably all convinced on their memories or let it go and worry about what else could be wrong with their memories and minds?]
It's probably better if you just try to forget it and go along with it either way. If that other person isn't someone bad or that you don't like, there's nothing wrong in taking advantage of the situation to make a new friend, right?
[ voice ]
[Yoh doesn't deny her optimism or her words. But the human mind is very narrowed and it's easy for it to miss things, specially regarding others' feelings.]
But if that's not the case and it's not a prank. Then it means that there's a problem indeed. You could check in with your neighbors or people whom you both know to see what they remember. If they remember the other person living with you two then it's most likely that indeed something has happened to your memory after all. But if they don't then the problem will be in their memories.
[But both options are just equally bad. Either Madoka would get upset because her memories are wrong or she would have to decide what to do regarding the other two. Confront them and upset them because they are probably all convinced on their memories or let it go and worry about what else could be wrong with their memories and minds?]
It's probably better if you just try to forget it and go along with it either way. If that other person isn't someone bad or that you don't like, there's nothing wrong in taking advantage of the situation to make a new friend, right?