To learn more about the things that we feel, we contacted London-based psychiatrist and author of 'You Are Not Meant To Be Happy. So Stop Trying,' Rafa Euba.

"Sadness is a natural emotion that we are meant to experience during certain periods in our lives," he told Bored Panda. "It is normally intermittent, like all our other emotions, and will come and go depending on what's happening at any given time."

"Sadness is more persistent during periods of adaptation to a loss when it will help us gradually reset our mind in response to that loss," the psychiatrist added. "The sadness we feel when we fail to achieve a certain goal, or that associated with unrequited love, may also help us re-evaluate our ambitions and lower our expectations. Sadness makes us withdraw and reflect for a while, which may result in better planning."

Even though it can knock us down, we shouldn't mistake sadness for depression. "Sadness is an emotion, which often comes combined with other emotions, both negative (like anxiety) and positive," Euba highlighted. "Nostalgia, for instance, is a generally pleasant emotion, even though it includes within it an element of sadness."

"In contrast, depression is a clinical condition, an illness that needs to be treated," he said. "In depression, negative emotions spiral out of control, generating enormous suffering. A depressed person feels sad and anxious constantly and for long periods of time, and typically finds it difficult to sleep, or to enjoy anything in their lives."

"So while emotions are fleeting and have functions that help us live our lives, a depressive illness has no function. It is a malfunction."

It's difficult to say just how much sadness is normal, as there can be a lot of variation in how different people process emotions, but, for example, a survey of 2,000 British adults discovered that on average, they spend three months a year in a glum mood, equating to 96 days a year, or eight days each month.

Interestingly, the new year doesn't start on a good note either, with a quarter feeling at their lowest during January.

Top winter gloom inducers include the weather, shorter days with dark mornings and evenings, and feeling cold. 

Spending time with friends and family is the top way people combat January blues, followed by listening to music, resting, and going outdoors.

That being said, the average person spends just under an hour a day outdoors in winter and estimates only 44 minutes of that is in direct sunlight.

Furthermore, one in five only gets between 1 and 15 minutes a day under the winter sun’s rays.

But just as sadness is a natural emotion, so are its remedies. Dr. Shelley James, director at Age of Light Innovations, said that bright light, especially in the morning, can help boost your mood in three naturally powerful ways: by helping the brain to regulate mood hormones, supporting alertness, and making it easier to fall asleep.

James noted that simply getting outside into natural daylight can sometimes be enough to top up your mood, as it boosts your body even when the sun isn't breaking through, as well as giving you a chance to get a little exercise.

"If you feel sad occasionally, bear in mind that this is just a natural emotion that is very much a part of our lives," psychiatrist Rafa Euba added. "Think of it as 'mental weather,' a natural fluctuation that will pass soon and will probably be replaced by a different emotion."

"Remember too that despite what you see in social media, we are not really meant to be consistently happy. Humans will always struggle with intermittent difficult emotions, which are there because of a set of very powerful biological and evolutionary reasons, so they are not going to go away any time soon."

However, if you suspect that you might be depressed, Euba advises you to seek professional help. "Treatment and therapy will help, and you will then be able to experience the normal range of human emotions (including occasional sadness) without the burden of your depression."

For more similar memes, check out our first publication on 'Mad Sad Not Good.'