1, haunted by dreams; It implies that you can't forget the person you miss, and your soul and dreams can't hide your thoughts about it.
2. Intention: It implies that you had a good relationship with that person, but you missed it for some reason, and you expressed deep regret.
3. Parting loneliness: It implies that you once met that person, but with the passage of time, you finally missed it, and now you feel deeply lonely and lost.