What would you do if you found out you had a long-lost twin?

Oh my god. At first I would probably stare blankly thinking I'm seeing things. T'ill her if she can wait one second go up to my Mom and tell her theres something crazy going on with my brain cause theres some person who looks just like me on the steps. Then she would admit I had a twin I would freak out on her for not telling me before. And then I would invite her in I would be the happiest person ever and we would be great friends.