Abandonment in a dream represents letting go of past feelings or hopes. Your subconscious wants you to move on with your life from a mindset that keeps you from moving forward.
Use the rest of your dream to figure out what you are letting go of. Is someone abandoning you? Did you have a fantasy or expectation of them in real life? Your subconscious is bad and communicating so it shows them abandoning you, but in actuality telling you to abandon the fantasy. Abandon the fantasy. You are still holding on to the fantasy even if to the outside world you appear to be moving on. Your subconscious wants you to let them go. And do so, or the dream will re-occur.
If you thought you let go, but it is strange to have this dream, a tiny little part of you is still holding on and is expressing itself in your dream.
If you are abandoning something or someone, your dream is telling you the same as the later. But in this case you know that you have work to do. You are letting go of the ideas or concepts you had of that thing in your life / you are letting go of the ideas or concepts that surrounds the person in your life… what they stand for in your life.
Your subconscious could also be telling you that you need to move on from an old frame of thought or belief system.
Start fresh and open your mind to different ideas.
In order to grow, you will need to adopt new beliefs.