Concepts are how we discern the borders of reality. We think in concepts, but how do we know that we think? If your thoughts are you, then who is the one listening?

Existence
Everything that has energy exists. We know this because the energy is collected by various wiggly energy collector things that have attached in some way to your mind.
People have this remarkable ability to classify things, that is to put a thing into category so that it can be understood in simpler terms. An example of this is a dictionary. A dictionary is a list of concepts. All these concepts in the dictionary... the hundreds of thousands of them, are man-made.
What is a being but something with the ability to understand concepts? All beings can understand concepts and can react to the ones they sense.

Tail
We say that an animal has a tail, because when we see a wiggly thing at the end of another wiggly thing and it is small and long then it is a tail.
How many concepts exist in that statement? More than 50!
And every concept is man-made. The concept of a tail is man-made. The concept of animal, vegetable and mineral is man-made. The concept of things existing in a hierarchy is man-made, as is the concept of the hierarchy itself.

Mutually Opposite
When we have a problem with the world that can not be solved it is a problem with the concept itself. It is our struggle to understand and accept that concept as being part of everything.
We say that there is a thing called 'good' and another opposite thing called 'bad'. We like things to have opposites because it helps clarify the meaning of the thing. This does not mean that 'good' and 'bad' are mutually exclusive. This is a man-made rule called 'opposite'. It is quite possible for something to be 'good' and 'bad' at the same time. But we like to keep them apart.

Origin
What is a concept? How does it influence the mind? The mind does not need concepts. When we are born we are unaware of the concept of concepts. We don't need it, don't want it. We simply react to our innermost needs. Air, Nutrition and Comfort. We don't care as a baby whether the food we get is of the highest quality or not, but we do react chemically to things entering us, and this information is very useful for keeping us alive, so we store the information and compare it to every other piece of information.

Three Concepts
Our first concept is a chemical one. We become aware of an emotional one, and that emotional reactions exist as something in the hierarchy of chemical reactions. This does not mean they are not valuable to us; the appreciable mechanism has not been afforded us at that moment.

Our second concept is a relative one. We measure how the new concept relates to the first. By the time we are born we are able to measure and understand concepts. We are a living being, we discover that everything exists in relation to everything else. It is a system.
The third concept is an intellectual one. Our brains and minds have developed and we are able to define our own concepts. We learn because we choose to learn.

Self
As we get older we are told about more concepts. Parents are so eager to pass down the concept of self, they spend hours with their children going 'dada' and 'mama'.

On/Off
Mama is a word known in almost all cultures. It is a curious word because it contains two phonetic extremes, the M is very difficult to discern from N, or a hum or an Oooooo. The A is very easy because it contains easily recognisable oscillations and can be discerned from other sounds easily. Sometimes children learn "NooNoo" which also means mother in many cultures, and it is almost the same and equally complex.
So we learn very early on to recognize the difference between hard-to-understand and easy-to-understand. Almost like the peaks and troughs of a wave. The center line being the average of the information our ears take in.

The Center Line
All concepts exist around a center line or center concept. Concepts all have degree, that is an amount of On-ness or Off-ness. Even On or Off can have a degree, they merely represent the instantaneous maximum or minimum.

The point is, concepts define themselves. We invent them. Every part of our society is man-made, based on the chemical needs and emotional needs of the average human being. This does not mean it is right or wrong, good or bad, concepts are a dissection of the continuity of existence.