Dreams as a concept has intrigued thinkers since the consciousness first perceived it, questions like what is it, why it happened puzzled them for a very long time. With the passage of time many cultures around the globe started conceptualize it, for example - Ancient Egypt considered dreams as divine messages, the Greeks and Romans believed it could tell the future. Notably Dmitri Mendeleev, the person who created the period table structure which we use today, claimed that he envisioned the structure in his dream.

While for a very long time, dreams were considered as a mystic and spiritual concept, modern neuroscience has started to understand the why behind it. You see, there might not be that huge separation between our sleeping and waking state, they both could be separated by a considerably thin line. Recent studies have shown that dreams play a very important role in our memory consolidation and its unification, emotional regulation and processing of daily experiences. Meaning, there is a reality that we experience in our waking state, and then it gets consolidated and regulated when we dream, ie. the states work in a complementary harmony for effective functioning of life.

To begin with their origination, the dreams originate from the electrical activity happening inside the brain, just like any other state of our consciousness. However a key difference is, that during dreaming the activity in the limbic system (a brain structure which is responsible for emotion, behavior and long-term memory) increases significantly as compared to when we are awake.

Another pondering point is, dreams are stimulus independent cognition, meaning they do not require external input to occur. In dreams our brain creates entire worlds and narratives without any sensory input from external environment, this itself is enough for us to wonder the incredible untapped capability of human brain.

Now the question would be, how do the dreams occur, and why they only occur when we are asleep. Studies have discovered that, for us to get into the state of dreaming, the brain's Central Executive Network (CEN) needs to shut off, this allows the Default Mode Network (DMN) or the Imaginary Network to take over, and this, this specific mode of brain is responsible for our dreams, and it only gets active when our executive network rests and we are not focused on the external world.

Next question could be, but why do we dream?, what is the need for it? Well, there are no absolute answers for this as of now, but several theories have tried to explain what could be a possible reason for it to occur. Some researchers believe that dreaming has evolved as a form of Threat Rehearsal, which we inherited from our ancestors, and it prepares us for the potential dangers in the waking life. Other suggests that dreaming helps us process, integrate and consolidate our daily experiences. Another promising theory says that the purpose of dreams is to introduce noise into our cognitive systems, which prevents our brain to become too specialized into its daily experiences, and this noise helps the brain to maintain its ability to generalize and adapt to new situations.

Interestingly, you would be surprised to know about the profound connection between creativity and dreaming. Dreaming creates a unique way to tap into the mind's creative potential. We already discussed that the brain operates in two modes - the executive network and the imaginative network. During waking hours, when we are focused on a task, involved in our work, the executive mind keeps us on track. However when we are not actively thinking like while washing clothes or cutting vegetables, the imaginative network takes over, and this particular state is more conducive to Eureka moments, when we suddenly solve a problem or conceive a brilliant idea.

Relatedly, in a study conducted with over 500 students, each of them was asked to focus on difficult brainteasers before going to bed. The returned results showed that about half of the students reported dreams related to their problems, with close to one-third of these dreams containing solutions.

We discussed above about Dmitri Mendeleev and how he got the visualization of the periodic table in his dream. But this is not the first time when someone reported this, if you would have taken Science in your 11th standard, you might be aware about the compound Benzene. Well as it turns out, the chemists in 19th century were puzzled about Benzene's structure, they spend days and nights in understanding it, and surprisingly the solution came into the dream of August Kekule, he envisioned a snake made of atoms biting his own tail, leading him to realize that the benzene's structure was a closed ring.