That doesn't mean anything. The only sense in which you can 'accept´ they are no longer part of your life is to not take action to force them back into your life when they don't want to.

Besides that, it is all subconscious. There is no decision. The feelings, the memories, they are either there in your mind, or not.

It is not even about being sad. Thinking about them can make you feel happy rather than sad.