Life happens, and despite our best intentions, we have no control over outcomes. Life changing events change us, often for the better. It's up to us to adapt and allow that change to happen so that we continue to grow and make the most of the time we have.
Life changing events include anything that alters your perception of who you are and your priorities. Getting married and moving to a different zip code; Having kids; dealing with healthcare issues or caring for a sick loved one; Changing jobs or being forced into situations that you aren’t prepared for.
Things change, you change, relationships change. Some people won't want to stick around for the difference. You have to decide how to cope, who to let go of, and when! Often, hanging on will only harm you further.