Sometimes you and someone else were only meant to share a moment of time with each other.
Sometimes friendships and relationships are not built to last forever, they are built to teach you a lesson. Maybe you both needed to learn something from each other that no one else in the world could teach you at that time. Maybe you both were perfect for getting each other through a terrible storm together.
In life you will fall out with people that you never thought you would. Get betrayed by people you trusted with all of your heart. And get used by people you would do anything for. But life also has a beautiful side to it. You will get loved by someone you never thought you would have. Form new friendships with people that will establish more meaningful and stronger relationships. And overcome things you never thought you would get over.
We all have chapters that end with people at some point in life. But take pride in knowing that the very best part of your book is still being written.