Au contraire, mon ami, speaking your truth is “a thing” — a very important “thing” — in everyone’s life. Censoring that “thing” particularly in our most important relationships — the most important of which is our relationship with ourselves — is a primary cause of mental illness.
Part One: in the abstract
Let’s start with fundamentals of epistemology.
Even scientific truth changes over time as we learn more about our world and all the prior mistakes and mistaken interpretations driven by faultlines in the theories of science that govern a particular field or discipline.
Gravity exists firmly in the see-touch world of ordinary physics. But it does not exist once you get away from the gravitational pull of whatever planet/moon you may be standing on. In outer space, there is no gravity.
The FORCE of your gravity changes depending on where you are located in the universe/galaxy. That is to say, the fundamental truths of Newton’s theory of gravity are relative.
That is to say, one of the most influential theoretical discoveries in the late 17th century, Isaac Newton's exploration of the force of gravity, turns out to be relative to one’s location in space.
Gravitational theory enables you find solutions to very practical problems, such as building skyscrapers that won't fall down. It works, but ONLY in the see-touch world of ordinary human experience. Once you leave the gravitational pull of a specific planet or moon, everything changes. Those changes have a science of their own, but what happens in space is outside the framework of Newton's physics.
Shall we have a discussion of Einstein's theory of relativity, particularly what happens to TIME in space? How about the nature of space as CURVED?
Have you read Fritjof Kapra (The Tao of Physics) or James Gleick (Chaos Theory) — two scientists who wrote books on what had become current theories in physics in a way accessible to well-educated but non-professional science geeks?
The concept of scientific certainty is hugely important in a world where crazy political idiots deny the efficacy of the scientific method, for example, in the production of, relatively safe vaccines. Equally important, the belief in unalterable “universal truths” led to the horrors of executions and demands that scientists like Galileo repudiate their discoveries.
If you want to be a scientist, you have to be prepared to let go of old premisses and conclusions even though doing so fundamentally alters foundational truths previously determined to be universal across the geographies of space and time.
Einstein upended what we “science simpletons” (and science professionals) once believed to be immutable “natural laws.” These “laws,” discovered by scientists like the long dead Newton, are now understood to be relative. You know…that “theory of relativity”?
Let’s take a brief detour to tackle the popular but erroneous belief that scientific theory is “mere theory” and therefore a construct of private, individual imagination.
Theory in science has its own “gravitational force.” Scientific theory is arrived at when scientists explore anomalies that don’t fit into existing presumably immutable theories. Once a narrative has been proven to explain phenomena previously inexplicable within “theories du jour” it rises to the status of scientific theory upon which we may rely, at least until we encounter sufficient observed phenomena that do not fit.
Once you get outside of the world directly accessible to our senses, (at least the usual five physical senses), the world of physics kinda goes "haywire."
Indeed in a world far outside what is accessible by our physical senses and their extiensions via instruments, two contraries can be simultaneously true. It just depends on a turn of a metaphorical prism. Best example: light has both of the presumed mutually exclusive properties of particles and waves.
These days — in a world full of anti-science idiots who somehow have access to political power — it can be downright dangerous to be talking about modern theoretical physics developed post-Newton.
But you also cannot claim that scientific knowledge as the average person understands it can be absolutely true in all occasions and situations.
The concept of "speaking your truth" recognizes that human experience does not follow immutable scientific laws. Human experience varies widely in the truths it holds. And sometimes those truths are contradictory.
Funny thing -- once people begin to open up about life experiences heretofore hidden behind closed doors and rarely talked about -- we find a great deal of common ground. Eventually science may enter and and end up backing common ground previously thought to resist scientific explanations. (See, for instance, "Childhood Disrupted: How Your Biography Becomes Your Biology, and How You Can Heal,” by Donna Jackson Nakazawa (Atria/Simon & Schuster, 2015).
When people say they are "speaking their own truth," they are not speaking of scientific truth.
They are speaking of their own life experiences and challenging other people’s perceptions of them. The "truth" of which we speak is the truth embedded how we understand our own lives as a consequence of serious and extensive self-exploration, often with the help of psychotherapy.
Speaking your own truth is grounded in the MEANING we make out the physical and emotional experiences of our lives. That truth comes down to our sense of ourselves as we examine the lives we have lived, informed by the social sciences (and now even physical sciences as per Nakazawa above).
Furthermore, those truths may undergo radical changes as contradictory new facts and long buried life experiences thrust themselves “through the looking glass.”