Bringing up Baby

While I was reading Brining up Baby I felt as if I were watching an episode of I Love Lucy. Here's a guy who loves a girl so much he is willing to put his life on the line for her to find a panther. Suzan seemed like a "Lucy type" very unexpected and indecisive and witty. At the same time here is David the "Ricky type", serious, and straight headed. However, any crazy thing she does he sticks by her. What I found unusual of the story is why is it so important to Susan to make her brother proud? Why Did she keep baby way before she found out it was for her aunt? Also why did David just stand and watch Susan make "an ass out of herself" when she was by the pajama - clad's mans house? I didn't get the topic or point that the author was trying to make. I found the reading to be comedic and how Susan gets a kick on going back and fourth with David. David himself says he can recognize a familiar gleam in Suzan's eye. And that gleam tends to happen when they argue or something interesting happens.