Think of your own attitude when somebody you don't know asks you for something. If a shabby stranger to comes your door, you're not likely to let him in; if a stranger comes to your door nicely dressed, shoes shined, hair perfect, with polite manner and a smile, you're likely to be much less suspicious. Maybe he's really Jason from the Friday the 13th movies, but you're willing to start out trusting that person as long as he looks normal and doesn't have a carving knife in his hand.