Here is where you can read Carl Sagan’s essay on the pleasures of getting high:

I can remember the night that I suddenly realized what it was like to be crazy, or nights when my feelings and perceptions were of a religious nature. I had a very accurate sense that these feelings and perceptions, written down casually, would not stand the usual critical scrutiny that is my stock in trade as a scientist. If I find in the morning a message from myself the night before informing me that there is a world around us which we barely sense, or that we can become one with the universe, or even that certain politicians are desperately frightened men, I may tend to disbelieve; but when I’m high I know about this disbelief. And so I have a tape in which I exhort myself to take such remarks seriously. I say ‘Listen closely, you sonofabitch of the morning! This stuff is real!’ I try to show that my mind is working clearly; I recall the name of a high school acquaintance I have not thought of in thirty years; I describe the color, typography, and format of a book in another room and these memories do pass critical scrutiny in the morning. I am convinced that there are genuine and valid levels of perception available with cannabis (and probably with other drugs) which are, through the defects of our society and our educational system, unavailable to us without such drugs. Such a remark applies not only to self-awareness and to intellectual pursuits, but also to perceptions of real people, a vastly enhanced sensitivity to facial expression, intonations, and choice of words which sometimes yields a rapport so close it’s as if two people are reading each other’s minds.