How does your subconscious go about producing hidden symbolic meanings in dreams?

What if in my dream something appeared only because it was something I just watched or heard the day before? Is my subconscious still using that means to express itself? (if I didn't just see or hear it in my waking life would it have got a different symbol that meant the same thing?) What about all the little things that can affect your dream, like waking up earlier, eating something else or engaging in something else? That all affects the chance that you would have a particular dream. Does your subconscious try to send the same message regardless of the different little things you decided to do at that moment? Would you still see a pattern if you were able to rewind time, do something else and would it be the same message? (I am only talking about little changes like pausing, going to bed earlier, eating something else, taking a nap, do a different activity, not big things that would obviously change your whole state like new goals or activities or things you wouldn't normally do).