system
surprised: My friend bought us tickets to my favorite band this weekend. He didnt even tell me. I thought it was sold out.
gpt
My friend just gave me a ticket to a sold out show tonight. He kept it a secret from me for two weeks. I had no idea.
gpt
You have an amazing friend!
gpt
Its my birthday too. I didnt think I would be able to go. 
gpt
Well that's awesome! I bet you will have a great time