This point is reminiscent of one of my favorite quotes by one of my favorite authors, C. S. Lewis.
Lewis says, “Friendship arises out of mere Companionship when two or more of the companions discover that they have in common some insight or interest or even taste which the others do not share and which, till that moment, each believed to be his own unique treasure (or burden). The typical expression of opening Friendship would be something like, “What? You too? I thought I was the only one.”