have you ever seriously contemplated what if somebody knows what you think?

Its really very scary, if someone can know everything about what you're thinking.

it's scary 

yea, scary.

Dude, I was so scared of my mom because of that :P haha

They know about us because they love more than we do to them, that is why they are too concern about our habbits, our way of treating them and others, so mostly these are guesses more appropriate would be they evaluate you more than what you think about them. If I will be talking to someone, I would be questoning them on several things, to evaluate them what they do, how they are living and what perceptions they have in their mind for several things, it will enable me to guesstimate their future actions depending on what they told me about something in past. Being nice to someone not always mean that they do not want anything from you in return, if they care that much about you, then you should also play your part.

That somebody would go crazy soon.