Sweet dreams are made of this, and real dreams are made of that. In all honesty, we still do not fully understand the amazing hocus pocus of the brain that is a dream. Dreams are understood to be the period of time where the brain rests and recharges itself for the day ahead. Dreams often feel as though they last the entire night, or for hours, but are often only 30 seconds to 30 minute in length, if not longer than that even. An interesting fact is that some people dream in black and white, while others dream in color.