Age difference, hidden feelings, and most importantly knowing each other since you could walk, but your in high school and he has his dream in his hands. He doesn't want you the way you want him, or does he.
You have no idea who Klaus Mikaelson is to you. You have no idea who any of the Mikaelsons are to you, for that matter. Thing is, they seem to know you. If what they're saying is true, how are you going to get your apparently missing memories back?