6. They know everything about your life.
Because they are always the first person you call when something momentous happens, they are always well aware about what is happening in your life. So much so, that you could completely switch places and they’d know exactly how to be you. Oftentimes, your other friends claim that you are practically the same person.
7. You guys hate all the same people. *Wink*
This is probably because the two of you are so similar – not only do you like all the same stuff, but you also despise the same things. You instantly know whether they like another person because you usually feel the exact same way about them.