Do NOT leave before the final credits are over.
I absolutely loved this movie! When the credits rolled I just sat there thinking about what a beautiful yet sad story it was. Lucky for me I did. Just like every Marvel movie I've seen, there's a little Easter Egg right at the very very end. You have been warned.
EDIT: There are spoilers in the replies below! Proceed at your own peril!
That's my 2 cents and no, you can't have it!