By "instantly clicking" I mean meeting someone for the first time and after a few minutes you
-have the feeling that you can truly be yourself around that person.
-feel like you can say or do anything you would around that person without upsetting them.
-have the feeling that you don't have to "dumb it down" for them.
-make jokes or say things you would otherwise keep to yourself.
Basically, the person seems totally in sync with you. You are also very relaxed around him/her. In short, you sense that the person "gets you" on a higher level.
Has this ever happened to anyone else? What exactly is this? Why does it happen?