a zombie
A zombie is like that ex who came back just to make you feel like you failed a test. They ghosted you, then boom, they’re back like they’re your new best friend.
"Hey, I’ve been thinking about you. Why? Because I forgot about you."
"You left me like a bad habit. Now you’re back like a bad day."
"I thought you were gone for good. You’re just a zombie in my brain."