I invited some people to my house for a get together and didn't think that many people would come.  In fact, I could only initially think of 5 people to invite.  The night came, and so did more than 15 people.  I was surprise at the turn out.
Hi!  I planned a get together at my house and was surprised.
user
What happened?  Do tell :)
assistant
I could only think of 5 people to invite, and was worried they wouldn't even come. But then...
user
Well.. I guess I will never know...
assistant
I was surprised because 15 people showed up and it turned out like a party!
user
Oh Snap!  wow... That was a surprise!  
assistant
It turned out to be a fun night.
user