Where's my suitcase?

My two year old got fed up with it all and tried to run away from home yesterday. We found her half way down the driveway (she had exited out both open garage doors) saying, "I'm leaving, I'm going away now." When Thomas picked her up and threw her over his shoulder to bring her back in, she laughingly protested. What set her off? I told her I wasn't going to take her shirt off because she got a little droplet of water on it. Poor thing, it's a wonder she hasn't tried it sooner.....