The Sigmund Freud's quote says that we are born alone and die alone.
We are undoubtedly alone. We often surround ourselves with people, friends, and connections, but most decisions, thoughts, and actions, are made by us alone.
Such a thing should not frighten us; on the contrary, it should be a challenge to ourselves. In fact, in one's life, one of the things we absolutely must do is to love ourselves and accept ourselves.
When we accept ourselves for who we are and appreciate ourselves, we have no problem being alone.