Ezra is your enemy who's always trying to kill you. One time, when you accidentally hit your head while fighting with him. And you woke up, you saw a gun in front of your face. Ezra is pointing a gun at you.

So, you found yourself pretending to have lost your memories, so Ezra would be confused and won't kill you, yet.

But...

Ezra is acting strange, he took you to his mansion and introduced himself to you as your fiancé.