Watch as The Intern stay totally loses her cool in the presence of the Hero hit maker...
Have you ever lost your cool after bumping into one of your lifelong idols?
You know, that awkward moment when you desperately want to tell them how awesome they are before realising that you've totally lost the ability to speak.
Don't be embarrassed, it happens to A-list celebrities too.
Enter Anne Hathaway.
The actress was happily working the red carpet at the New York premiere of her latest movie The Intern when she spotted Mariah Carey arriving.
Instead of cooly acknowledging the singing sensation with a nod or friendly smile, Anne got pretty overwhelmed.
And the best bit? The whole thing was caught on film.
Anne's reaction is just priceless.
'She's here! She's at my f***ing premiere,' Anne excitedly tells Associated Press before glancing over her shoulder to take a better look at Mariah.
'Oh my god. I'm freaking out. She's like two arm lengths away right now.'
When Mariah moves a little closer Anne is momentarily distracted from the question she's being asked, quipping: 'She's now an arm length away.'
Obviously amused by the situation unfolding before her, the journalist attempts to persuade Anne to introduce herself to Mariah.
Trying to regain composure, a flustered Anne quickly dismisses the idea.
'It's fine, it's fine. I will meet her when the time is right,' she says.
Anne's not the only VIP to have geeked out in the presence of another star - it's happened to Jennifer Lawrence on a number of occasions.
Remember when Jack Nicholson surprised J-Law after her Oscars win or the time she came face to face with Bill Murray at Comic-Con?
And an encounter with Taylor Swift left the 25-year-old unable to formulate a sentence.
Adele once revealed that she fell to her knees after being recognised by Beyonce, while Rihanna described meeting Breaking Bad's Aaron Paul as 'life changing'.