'I estimate that I have visited 312 houses since the first invited me in. People are stupid, you know. They pretty much all keep their keys in the same place. It's usually in, around or under the letterbox, mat or pot plant. It's not breaking and entering if the residents practically let you in. Also, I never broke anything really important. Never ripped up passports or birth certificates or anything like that. I could have, if I had wanted to...'