There are experiences that most of us are hesitant to speak about, because they do not conform to everyday reality and defy rational explanation. These are not particular external occurrences, but rather events of our inner lives, which are generally dismissed as figments of the imagination and barred from our memory. Suddenly, the familiar view of our surroundings is transformed in a strange, delightful, or alarming way: it appears to us in a new light, takes on a special meaning. Such an experience can be as light and fleeting as a breath of air, or it can imprint itself deeply upon our minds. … Many persons also have visionary experiences in daily life, though most of us fail to recognize their meaning and value. Mystical experiences, like those that marked my childhood, are apparently far from rare.

- Albert Hofmann, in LSD : My Problem Child (1980)