What is time and what is its nature? Often ideas about this are unexpected and paradoxical, regardless of who expressed them - philosophers, physicists or biologists. Any of us would like to manipulate time - to correct past mistakes, in order not to grow old, in order to have the ability to change future events. So what is time? What does it consist of and how does it move? Is there reversibility of time? How is time perceived by the human brain and what are the differences in its perception among different peoples of the world? Why does time fly faster for us as we age and why do we age? All this will be discussed in this book. The publishing layout of the book is saved in PDF A4 format.