I think it's called trust.
Sometimes debris is removed from our life. We try to hold onto it, we think it's good to have in our life, but then realize we are better without it and it's best to let it go. Sometimes it's for a time and sometimes it's forever.
What are things you have had to let go of? It can be people. It can be stuff. It can be an attitude or opinion, or grudge or a relationship. The list goes on....
Let it go. If it's meant to be, if you're meant to have it in your life ... you'll know.