Profilers Crime Time discussion

Ok, I just have a few questions before I read any more of this book. 1.) Why does Hannay let some strange man into his apartment without any type of inquiry? I know this happened years ago when times were slightly different, but were they really that different? 2.) Why would Hannay let this fellow remain in his house after he is told a fantastical story complete with a dead body and a government conspiracy? 3.) After all this, why does Hannay give this strange(r) a straight razor "to shave?" Very bizarre & unsettling.