This can be used as a metaphor in literature but the real best use of it is when it comes to dream interpretation.
If you have a dream in which you are dumped then this can have very serious interpretation about your daily life. Of course it could also just be a reaction to actually getting dumped by someone. Did someone kick you to the curb or treat you like you were not wanted; were you thrown to the side in real life as if you did not matter? If this is the case then you must feel like you have been seriously dumped and if you have then you will probably be having dreams about being dumped. Of course there are other types of rejection in life that can be equally embarrassing, and sometimes suffering through another type of rejection is all it takes to have a dream of being dumped by someone. Maybe you volunteered for something and ended up sending in your application too late even though the fact that it was too late was clearly mentioned on the application space. This would likely make you feel pretty bad, especially when you were told that when you were turned down. The more public the spectacle, the harder it is to deal with too. If you are rejected in any way in real life and it made an impression on you in some way, then you are more likely to have a dream where you are dumped.
If you have a dream about a dumpster, then this dream may come to you because you are thinking about how annoying the tasks in your life have become, you wish that you could just toss all your problems in a dumpster and be rid of them once and for all. This is a possibility for why you are dreaming about this for whatever reason. Basically, you hate all of the things that are going wrong with your life right now and you wish that without altering anything else, you could just throw out and get rid of those few problems which are giving you the most…well, problems.
If you have a dream where you are dreaming of a dump truck then this could mean several things. For one this could mean that you need to go to several routes in the street that is your life to get rid of a lot of old emotional baggage and old mind garbage. Perhaps you have been thinking about how cluttered your mind had been lately and you have been trying to get rid of what seemed like excess information or useless pointless info. You’re tired of all of the soul searching and you just want to get rid of as much of it as you can for the sake of your future well being, well this is one reason that you might be dreaming of the dump truck. The dump truck can be a powerful symbol but it is connected very closely to specifics so if you can’t place the significance it would have had then it would be near impossible to interpret otherwise.