What is the subject line for this email?

Uncle Clark, It just dawned on my that I never really thanked you for our visit. All four of us had a great time. It was so good to see all of you and especially great to see the kids get together and have so much fun. I really regret that as I was growing up, we really did not see that much of each other( and by we, I mean the Kansas group and the Girons). But even given that, I feel as if you all have been part of my life and every time we get together it's like we have always spent alot of time together. I guess that's why they call it family. So once again, thanks for your hospitality and we look
Visit