This is a bit like asking whether a person who is blind from birth sees the colour black when their eyes are closed; however, I will try and answer your questions.
MoonMetropolis wrote:
...that you've never experienced in real life, would you consider it a real
emotion that you are capable of feeling in real life, or just something
that your subconscious mind created, that has no basis in reality?
Yes, I think it would be possible to feel that emotion in real life, although in reality it might not express itself the way it did in the dream. For example, when you experience Jealousy you might feel angry in the dream and disgusted in real life.
Quote:
Do you think it would be possible to feel an entirely new emotion in a dream; one
that no one has ever felt - or could possibly feel - in real life?
Not sure. It's possible to experience emotions in a dream which you haven't experienced in real life, such as love, but then it would be based on emotions you had felt and things you'd read/heard about what love feels like. I have, in both dreaming and waking life, experienced an emotion I don't have a name for, however.