Did you know that "random people" in your dreams aren't really random people? You've seen them before, whether it was on the street, or in your school or where ever. You might have even seen them just driving by in their car. You had forgotten them, but your subconscious hasn't.

So next time you have a dream that has a "random person" in it, just remember that you actually HAVE seen them before. And maybe they have had dreams of you, too.