It means that you are stuck on a thought. You might be thinking about anything all day long. That thought might have come to your mind and you stuck over that.
When you dream about yourself flying, it only means that you enjoyed your daytime.
Isolated from its context, an image of a zebra has no specific symbolism. Dreaming of a zebra in a circus or in the zoo would be very different from a dream of a zebra in the African wilderness or a zebra wandering through a mall.
That you need a vacation.
It means that the mud indicates dirty things. You dream yourself with mud. This means that you imagine yourself with dirty things.
The people in this dream represent various parts of yourself, characteristics in your own personality of which you are ashamed or embarrassed, or that you would like to escape.
It is entirely natural to dream about the mundane activities of life. Such dreams do not necessarily have any particular significance unless some intense emotion is involved or something quite unusual occurs in the dream. Dreaming about the mall probably reflects your pleasure in shopping.
It probably means that you are angry with yourself. The cousins in the dream symbolize the various aspects of yourself, and the many ways that you are too critical of yourself.
it means to stand up for yourself
No. Dreams originate in your own mind, not sent by anyone outside yourself. It is more likely that you would dream about a particular person whom you want to see.
I would say that it means that a part of yourself that you pretend to accept is something that you need to address. In essence, you are rejecting a beautiful, or desirable part of yourself.
In this dream, your sister represents some part of yourself or some period in your life. Dreaming of hiding her suggests that you would like to conceal or forget about this particular part of yourself.
Colloquially you can use either, but if you were to say 'in the mall' you would likely be referring to an object. There's a bookstore in the mall. If you said 'at the mall', you would presumably be referring to a person. Where is John? He's at the mall with his girlfriend. Of course, 'mall' can mean the physical building complex, in which case anything can be 'in' the mall, but 'at the mall would almost always refer to a person.