Albert Hofmann in LSD - My Problem Child (pp. 51-52):

"The horror shortened and gave way to a feeling of good fortune and gratitude, the more normal perceptions and thoughts returned, and I became more confident that the danger of insanity was conclusively past. Now, little by little I could begin to enjoy the unprecedented colors and plays of shapes that persisted behind my closed eyes. Kaleidoscopic, fantastic images surged in on me, alternating, variegated, opening and then closing themselves in circles and spirals, exploding in colored fountains, rearranging and hybridizing themselves in constant flux. It was particularly remarkable how every acoustic perception, such as the sound of a door handle or passing automobile, became transformed into optical perceptions. Every sound generated a vividly changing image, with its own consistent form and color. [...]

Exhausted, I then slept, to awake next morning refreshed, with a clear head, though still somewhat tired physically. A sensation of well-being and renewed life flowed through me. Breakfast tasted delicious and gave me extraordinary pleasure. When I later walked out into the garden, in which the sun shone now after a spring rain, everything glistened and sparkled in a fresh light. The world was as if newly created. All my senses vibrated in a condition of highest sensitivity, which persisted for the entire day. [...]

What seemed even more significant was that I could remember the experiences of LSD inebriation in every detail. This could only mean that the conscious recording function was not interrupted, even in the climax of the LSD experience, despite the profound breakdown of the normal worldview. For the entire duration of the experiment, I had even been aware of participation in an experiment, but despite this recognition of my condition, I could not, with every exertion of my will, shake off the LSD world. Everything was experienced as completely real as alarming reality; alarming, because the picture of the other, familiar everyday reality was still fully preserved in the memory for comparison. Another surprising aspect of LSD was its ability to produce such a far-reaching, powerful state of inebriation without leaving a hangover. Quite the contrary, on the day after the LSD experiment I felt myself to be, as already described, in excellent physical and mental condition."