"If I met Kat..." - just think, if you met Kat, what would you tell her? Maybe you've meet Kat live and you want to share with everybody your memories.
My turn If I met Kat, I would tell her how much I love her and take a pic with her I'd like to sound antural but probably I'll forget my English if I met her;x It'll be sth crazy, I'm sure!