Thanks for the helpful reply! I also enjoy the social engineering/psychology aspect, I'm heavily involved in phishing campaigns for user awareness, and it's interesting to see the techniques which do and do not work.
We also do a fair bit of physical social engineering, attempting to enter offices and so on, and have had some quite worrying results!
It's amazing what you can get away with when you keep the concept of appearing as if you own the place in mind. I can walk around a private place easily by carrying myself that way. You've seen the guy who used a safety jacket to walk into all sorts of places, right? haha