Leaving the house wide open.
It seems to happen to me about 2 times a year. I come home from work, and was so tired, and distracted, that I left my truck and garage door wide open. I awoke at 1 am to my daughter waking up so I went and put her back down. I went back to bed to hear a noise and jump out of bed, as I knew I had left everything open. I immediately went outside, and it was just my neighbor leaving for work, he works for ups at crazy hours. So I locked everything up and went back to bed.