The universe is, instant by instant, recreated anew. There is in truth no past, only a memory of the past. Blink your eyes, and the world you see next did not exist when you closed them. Therefore, the only appropriate state of the mind is surprise. The only appropriate state of the heart is joy. The sky you see now, you have never seen before. The perfect moment is now. Be glad of it.
Terry PratchettOf course, it is very important to be sober when you take an exam. Many worthwhile careers in the street-cleansing, fruit-picking and subway-guitar-playing industries have been founded on a lack of understanding of this simple fact.
Terry Pratchett