The ability to remain and maintain a state of calm is a daily challenge. It has a direct link to performance, for example, about 90% or so of top performers are skilled at managing their emotions under stress; they remain calm and in control for the most part.
Stress can wreak havoc on your physical and mental health. Prolonged stress causes degeneration in the area of the brain responsible for self control; however, stress is a necessary emotion that needs to be managed and balanced.
Our brains are wired in that it is often difficult to "take action" until we feel some level of stress (it is a motivator). Ironically, the onset of stress entices the brain into growing new cells responsible for improved memory. When the stress continues beyond a few moments, into a prolonged state, it suppresses the brain's ability to develop new cells.
Intermittent stressful events keep the brain more alert, as we tend to perform better when we are alert. As the human brain continues to evolve and increase in complexity, we develop the ability to worry and perseverate on events that create frequent experiences of prolonged stress.
It increases the risk of heart disease, depression, obesity, and decreases cognitive (mental) performance. The bulk of our stress is subjective and under our control. Work towards developing coping strategies that work for your stress level.
Put it all together and work at it. This process is not an overnight, microwave way of doing things, it takes, time, work and energy/effort to accomplish short and long term goals of overall health and well-being. It takes effort to promote change---Be the change you want to see and stop judging others! (Entrepreneur.com/"10 Ways Smart People Stay Calm"-Travis Bradberry/Rochelle Payton).