Maybe it's your way of defending yourself, because you've experienced maybe betrayal or abandonment? So, maybe you don't wish to invest so much in
relationships. But, maybe too you can reflect on those past relationships, and
view them from the perspective that there was time together that was valuable,
and people parted for various reasons. Leaving you to fill that void again.
But - you can still care, and be a caring person. Hopefully, your friends will have the sense to realize this.