What's the big idea?

Andrew is constantly cracking me up with little sayings that he picks up. A few weeks ago I was at Lisa's house saying goodbye to Andrew. I caught him and gave him a suffocating hug. He pulled away and put his hands on his hips and said, "What's the big idea?" I couldn't stop laughing. I still laugh when I think about it. Last Sunday he was running in and out of my parent's living room saying, "What's going on here?" This is while he was wearing his monkey pajamas yelling "I'm a monkey, I'm a monkey!" This picture was taken at a bowling alley in December. He didn't want his picture taken. He must get tired of the paparazzi.