You have to understand that PTSD has to be an event that you experience, a very traumatic event. And actually, there is evidence that brain chemistry changes during this event in certain individuals where it's imprinted indelibly forever and there's an emotion associated with this which triggers the condition.

A book is made from a tree. It is an assemblage of flat, flexible parts (still called "leaves") imprinted with dark pigmented squiggles. One glance at it and you hear the voice of another person, perhaps someone dead for thousands of years. Across the millennia, the author is speaking, clearly and silently, inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people, citizens of distant epochs, who never knew one another. Books break the shackles of time ? proof that humans can work magic.

What an astonishing thing a book is. It's a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles. But one glance at it and you're inside the mind of another person, maybe somebody dead for thousands of years. Across the millennia, an author is speaking clearly and silently inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. A book is proof that humans are capable of working magic.

"What you see will remain imprinted in your mind and will have impact on you in many ways

"It's strange, isn't it, how you never know you're living the best time of your life at the moment you're living it? If you could appreciate, at that instant, that this is it, maybe you'd make certain your mind imprinted every detail of the sights, smells, sounds and sensations.

I don't have a diary, I don't write things into a diary. I imprint myself into the sky and when the sunlight shines brightly, I can stand under the sun's rays and everything I have imprinted of myself into the sky, I will begin to see again, feel again, remember. And when the wind begins to blow, it blows the details over my face, and I remember everything I left in the sky and see new things being born. I am unwritten.

Everything you'll ever need to know is within you; the secrets of the universe are imprinted on the cells of your body.

Traditionally scientists have treated the laws of physics as simply 'given ' elegant mathematical relationships that were somehow imprinted on the universe at its birth and fixed thereafter. Inquiry into the origin and nature of the laws was not regarded as a proper part of science.