Thats when you remember the times this person has stood beside you. Recall the good times that you enjoyed with this person. List out the billion reasons why this person is in your life in the first place. It takes just as much effort to think ill of a person than it is to think good of a person.
I believe in seeing good in everyone. People call me naive, unaware, innocent and maybe even oblivious for this reason, but I believe in giving people second chances. It might not come naturally to me, but I would rather spend energy thinking about how a person can be "good" than how a person can be bad.
There was a time when friends walking out of my life for various reasons took the life out of me. I still care about all my friendships the same way as I have before, but now I can cope with losing friends better. I don't want to tie anyone to a relationship/friendship that they are not comfortable in. I try to learn from my shortcomings and I try to improve myself. But people walking out of my life is no reason to reject people walking into my life.
After a long journey of toil and ponder, I have made my peace with this. I learned to not be judgmental based on past friendships because every new person calls for a new friendship. I learned not to be disheartened by the constant change of friends in my life because each person I met left a mark in me that I will cherish forever. Most importantly, I learned to be more welcoming, giving and serving in my friendships.
It still is a struggle, but at least now I have a starting point..