Late-night snacks can cause nightmares: Nightmares in adults are much less common than in children, but there are some factors that can trigger scary dreams. Besides stress, medications and depression, late night munchies can interfere with your body's metabolism. Eating late will make your brain feel like it needs to stay active for your body, which can lead to crazy dreams if you fall asleep instead of use up your energy. Dreams occur all the time, not just during REM sleep: Doctors and scientists used to believe that dreams could only occur when people were in their deepest cycles of sleep, or REM sleep. In fact, dreams can occur at any time, though dreams you have during NREM sleep are usually less intense and less vivid. The National Sleep Research Project proposes that "it's possible there may not be a single moment of our sleep when we are actually dreamless." Day dreams are real: The psychology department at UC Santa Cruz explains that our bodies and brains don't necessarily require actual sleep to dream. As long as certain forces are in effect and the environment is right — when we tune out external stimuli but our brains are still active, for example — we have the potential to dream. Smells affect your dreams: A 2008 German study found that positive and negative smells affect dreams: positive smells result in positive dreams while negative or unpleasant smells result in bad dreams. Blind people don't "see" in their dreams: For people who can see, it can be hard to imagine dreaming without lifelike imagery. But blind people dream, too, though not in the same way. According to The Accidental Mind, people who were born blind or who became blind at a very young age generally experience dreams according to their other senses. The act of dreaming may be like watching a movie: The National Sleep Research Project explains that when you dream, your eye movements react differently during different parts of your dream. Scientists equate this eye movement with the same way you watch a movie. When you wake up determines whether or not you'll remember your dreams: If you can't remember your dreams, there's no need to worry. Whether or not you remember your dreams is determined by when you wake up. If you wake up in the middle of a dream, for instance, you'll be much more likely to remember it than if you wake up after you stopped dreaming, or even during a less significant part of your dream. Your dreaming ability matures by 5th grade: Young children do dream, but UC Santa Cruz's psych department explains that their dreams are usually more "bland." We don't realize our dreaming potential until 5th grade or so. Dreams help depression: It's still debatable whether or not dreams hold any true meaning, but many scientists do believe that dreaming is therapeutic, as it lets your mind freely associate to feelings and explore emotions. Your vitals are similar to your waking self when you dream in the REM cycle: You might think that sleeping is all about relaxing, but when your body reaches the REM cycle, your heart beat, breathing and facial movements increase to a level similar to that of being awake. Night terrors affect you when you sleep and when you're awake: Night terrors usually occur in children 4-12 years of age and are much more intense than nightmares. Sleepwalking may occur, and also unlike nightmares, they last even after you've woken up. Scientists believe that night terrors happen earlier in the night for kids, but at any time of the sleep cycle for adults. iPads and other tech gadgets can make you have crazy dreams: Reading a book in bed is a good way to fall asleep, but not if you're reading your iPad or similarly faux-lit object. The unnatural glow from gadgets keeps your brain active, which can trigger restless sleep and even nightmares or crazy dreams. Your body uses outside influences to keep you asleep: Unless you are in a very deep sleep, your body tries to use external forces — like music or other outside noises — and incorporate them into your dreams as a way of keeping you asleep. You're more sexually aroused when you dream: Just as your heart rate and breathing increase when you're in the REM cycle and ready to dream, you become more sexually aroused, too. We forget 95-99% of our dreams: Sometimes, dreams make such an impression on our conscious minds that they're hard to forget even days later. But for the most part, we forget the majority of the dreams we have each night. Scientists even calculate that we dispose of the memories of 95-99% of our dreams. This tendency to "forget" could be from the fact that we aren't even paying much attention to our dreams as they occur.