''Thank you and I love you'' i think I've heard it before but I can't remember

same with me, its like dejavu for something i read or heard? (●'◡'●)ﾉ

I think I've read it it the founder of diabolism but It was a little different. I think it was ''thank you and I'm sorry'' but it's been a long time since I've read the novel and I don't remember