You open your eyes, see the all-too-bright light through your window, and immediately wish you weren’t awake. Closing your eyes, you imagine you are still driving a Ferrari or stuffing your face in that bowl of chocolate ice cream. But, just as suddenly as it came, your dream is gone.

Almost everyone has experienced this feeling. For the brief time that you remember a positive dream, you often wish you could fall back asleep and watch it play out again and again. Unfortunately, of the few things scientists know about dreams, they know you can rarely resume one.

In order to know why we dream, it is important to know where dreams come from. According to the National Library of Medicine (NLM), dreams are vivid hallucinations that occur during specific stages of sleep. They originate from the hippocampus, which lies deep inside the temporal lobe of the brain. Because the hippocampus is also responsible for memory control, your brain pulls from moments of reality and memories of your life to create a seemingly unique experience.

“The feeling of déjà-vu corresponds to the memory of an unconscious daydream. Fellow philosophers and I have also hypothesized that dreams provide the fragmentary memories later duplicated in a déjà-vu experience,” NLM researcher Jonathan Curo said.

Although scientists are not sure why we dream, there are, according to Healthline, several uses our brain might get out of dreams. One role our dreams might serve is training our fight or flight response. By simulating fight or flight situations, our brain gets used to making the best instant decision in a difficult situation. This type of training occurs in high-action dreams, which are very common.

“I once had a dream that I was late for class, and as I was running up the stairs, they started to fall and break apart. I had to run really fast so I didn’t fall into the abyss,” sophomore Tyler Epstien said.

Another purpose of dreams is to exercise creative tendencies. When we are awake, our filter of logic can prevent us from fully using our artistic and expressive left-brain tendencies.

“I had a dream a couple days ago that I was a fashion designer for Taylor Swift during her tour. It was very strange but also enjoyable,” sophomore Morgan Jacobson said.

Of course, not all dreams consist of rainbows and butterflies, as they also sometimes serve as a negative coping mechanism. According to the Cleveland Clinic,  negative dreams, or nightmares, can be a result of PTSD, stress, and irrational fears. Nightmares are also more likely to reoccur than positive dreams because experiences of fear develop stronger neurological pathways than experiences of joy.

“I’ve had many dreams before where I was being chased but I was stuck in place and couldn’t move,” sophomore Peyton Kragskow said.

Cultural and geographic factors also play a role in the type of dream you have had. For example, two students in Omaha are more likely to have the same type of dream than a student in Omaha and a student in Germany. This is due to the fact that our experiences shape our dreams.

“I often relate to dreams my friends have about school, because that is where we spend the most of our time,” Epstein said.

Of all the times you have discussed dreams throughout your life, you have most likely encountered someone who claims not to dream. However, according to Wonderopolis, every human dreams around every 90 minutes per night, amounting to twelve or more dreams. Those who claim not to dream simply don’t remember their dreams as the brain’s recall hormones are the lowest during sleep.

So, next time your alarm goes off in the middle of your sports car joy ride or ice cream binge, take a minute to reflect on the “experience”. Chances are, you won’t remember the dream for long.