Friendship is a wonderful thing and is vitally important for personal growth and success. It can be found on the Ninja's Kongokai mandala used in Japanese Mikkyo esoteric mind-science training. Found in the 'wind' realm which represents surrendering oneself to a greater good where the total result produced is equal to much more than just the sum of the parts added together.
Friendship itself is sometimes sparked by what we call "vibes," or a strange and electric power of attraction. This is what gives it such a terrific and seemingly magical power to tie people together so closely. All the same, our first impressions can often be mistaken. We've all made mistakes before in the friends we've chosen. Often, we'd like to ignore, forget, or believe that we had anything to do with the selection, but we shouldn't. It's these lessons that remind us that we are human and make mistakes, as-well-as the fact that not everyone we meet will enter into a relationship (whether business, personal, etc.), for the same reasons that we do. It's not right or wrong - good or bad. It's just life.