Created in the early 20th Century by the Austrian-British Philosopher Karl Popper, Falsifiability - also known as the Black Swan Fallacy - is the scientific process of callenging ones statement, hypothesis and/or theory to be proven false.
"True ignorance is not the absence of knowledge, but the refusal to aquire it." - Karl Popper
The issue with scientific theories is that they are created by humans. Scientists, like everyone else, can fall victim to confirmation bias, subjectivity and selective perception. A scientist trying to proof his theory to be correct, after already being internally convinced it is correct, naturally offers a lot of potential for errors and fallacies.
The process of falsifiability approaches this issue by stating that a valid scientific hypothesis requires not only verification, but also the proof of being irrefutable.
For example: If a scientists hypothesis is that all swans are white, first he will need to verify that. Said scientist is now on his way to verify that all swans are white, but by doing so he eventually misses out on a black swan - hence the name Black Swan Fallacy.
Thus said scientist would to additionally try to refute his own hypothesis by actively trying to prove it wrong.
"No amount of experimentation can ever prove me right; a single experiment can prove me wrong." - Albert Einstein
While this concept originated in the field of scientific philosophy, it also holds plenty of value in our everyday life. Life is a lot about our mindset, and opinions we hold need to be thought-out.
How often have the car-drivers of us thought: "The traffic lights are always red"? Instead we should put our focus on how often we were fortunate enough to have a green traffic light. That doesn't only disprove the hypothesis itself, but also helps to create a more positive mindset.
Unfortunately we focus way too often on negative experiences and create an unnecessary negative mindset. With more attention to positive events and disproving our negative mindsets we will be able to create a more balanced and healthy outlook.
Opinion-building and adjusting is another important aspect where the process of falsifiability is of importance. While developing firm opinions and views is appreciated and necessary, many people seem to avoid having them challenged. Just like explained, it is of utmost importance to do so. Our opinions and views need to be challenged in order to be truly firm. Backing away from having those challenged equals admitting that they are too weak to standing up to the task.
Thus it is up to each one of us to allow ourselves to be challenged and try to disprove our own opinions and views in order to stabilize and strengthen them.