When is an Opposum just an Opposum?

This never happened before...last night, in the middle of a deep, dream-less sleep, the Lovely Carla and I were startled awake by a fat little animal trashing around in the ivy outside our bedroom window (we are on the second floor!). The little critter seemingly tumbled out of the sky, and landed at our windowsill. I got up a watched as it slowly, noisily walked the walls of Ivy like Spider Man. I got back in bed, and told the Lovey C. not to worry, it was just an opposum. Her response: "Are you sure?" "Yeah." The Lovely C. again: "This must mean something." Sunny Jimmy: "Yeah, it must mean something." I went back to bed wondering what it must mean...