(one) never thought (one) would see (someone) here
Said when one is particularly shocked or incredulous about someone's arrival. Well, I never thought I'd see you here! What brings you to my Bible study group? Honestly, your mother and I never thought we would see you here.
(I) never thought I'd see you here!
I am surprised to see you here. Tom: Hi, Sue! I never thought I'd see you here! Sue: Hi, Tom. I was thinking the same thing about you. Bill: Well, Tom Thomas. I never thought I'd see you here! Tom: Likewise. I didn't know you liked opera.