A: When you are no longer clinging to them.
Q: How do you know when you are no longer clinging to them?
A: You are no longer clinging to them when you no longer have pain over them. When you no longer allow yourself to suffer. When you have peace and you can smile when you think of them. When you have accepted that they are now living in another dimension, but living nonetheless. You can still miss them, you can still have tender tears, but it's the pain and suffering about it that must be severed from your being. The pain and the suffering weave together to create the leash that binds.