It always happens. We meet a person, date them, fall deeply in love, and then love them so much that we practically run them away. What do you think that is about? A lot of people ask themselves, "I loved them so much, why did they leave?" This does not only apply to people we are dating. It also applies to our loved ones. I hear parents say all of the time, "I loved her so much, I don't know why my child would grow up to be like this. I thought I raised her so well." I think that the answer is within your question. Many people confuse love with "possession" or "attachment" when none of the terms are relative. Sometimes, when we find ourselves loving a person, we develop this weird fear of losing them. That is where attachment comes into play. A lot of us don't know how to love without trying to possess. At the end of the day, that person is still going to be who they are, and it has absolutely nothing to do with you.
Think about it like this: you approach a river to get some water. How are you going to go about obtaining this water? Are you going to grab the water, and clench it tightly with a closed fist? Or are you going to cup your hands together, and gently receive the water? I'm going to assume the latter. This is exactly how love works. When we try to possess it, it runs from us...but when we approach it gently, we draw it to us. My dad gave me that metaphor a long time ago, and I still apply it to my everyday life.
Loving without attachment does not mean that you don't care about the person. It more so refers to that unconditional love that everyone deserves. Loving without attachment is simply loving a person, with absolutely no dependence on them for your happiness. If you can love that person regardless to what they do, then you are loving at person without attachment. You cannot love someone fully if your love comes with conditions.
Loving without attachment takes work. In order to achieve this type of love, you must first learn to love yourself completely. When you truly love yourself, you don't depend on others for your happiness, because you know that true happiness comes from within. At that point, you will be happy even if your boyfriend decides not to text you today. You will be happy, even if your son doesn't invite you to his wedding. Not only will you be happy, but you will still love them the same.