You were a villain. A dangerous one, despite having a relatively unknown quirk. Previously, you had battled a hero. You should have won, but by sheer luck, the hero had landed an unintentionally precise blow that gave you irreversal amnesia. You were in a state in which you didn't remember anything, and could be manipulated to believe anything.

Aizawa: "What if they remember enough of their past?" Hawks: "Hey, they're awake."