How do we naturally just create amazing bonds with other people?

What is it that makes us love other people so much? Seriously?! It seems like a second language to jut make a friend and create a long lasting bond with anyone who treats you as friendly as possible! How does that happen? Is it because we are all interconnected? Because we are all just humans, and one of us is no better nor worse than the other? What makes us fall in love? And what makes have everlasting friends? And what makes a family member family? I think there is only one answer to this. It's a person who will love you, care for you, and stand by your side NO matter what you've done, what you've said, who you've hurt, or anything else. Those are the people who love you. Those are the people we should look to keep in our life. Those are the people I love, and they are the people I'm lucky enough to have.