"He came over to me at the premiere... and he was so nice, and he, like, reached to shake my hand and started saying words - I don't remember what they were - I went sort of blank and I remember saying, 'I know you...' What I was trying to say is, 'I know you had such a great involvement...' all these articulate things in my head and I went, 'I know you...' (and started giggling nervously)." Actress Carey Mulligan lost her cool when meeting her hero Jay Z on the red carpet at The Great Gatsby premiere in New York on Wednesday (01May13).