Don't tell everything ..:: Always have a way to keep your ego unaffected ::..

This one is going to be short.
I noticed that most people put conscious effort in keeping some thing about them-self secret [some business, girl friend, their monetary status/how much they earn], and after a short research and testing in real life I got to a conclusion that consciously keeping a secret emulates a feeling in you like you are the superior in the interaction [feeds your ego, no mater what happens you know something that no one else knows].

So there you have it, don't be nice guy and make yourself more mysterious [even if you have to fake it]