You're joking, right?
You've got to be joking./You're kidding.
I was completely surprised.
The news came out of nowhere.
What a surprise.
What a shock.
I can't believe it.
A: I've got some good news to share with you. I just found out that I'm getting that promotion that I've always wanted.
B: Really? That's wonderful.
A: I was completely surprised when she said she wanted a divorce.
B: You must have been in shock. Let me know if there is anything I can do for you.