"I can't imagine why!"

I had a baby when I was very young, and I tried to raise him. When he was four years old, I let my parents adopt him so that I could grow up. I ultimately thought that this was a good idea, because if I couldn't even take care of myself, how could I take care of a baby? 

I moved to Florida and my son stayed with my parents. About two years ago, I was planning to visit them. I was on the phone to my mom, and she said, "Oh, he's so excited to see you! Although I can't imagine why!" Then she followed up with, "Oh, I'm just kidding!" 

Our relationship hasn't really been the same since, and my mom and I don't really talk anymore.