This is also the day in which Albert Hofmann first experimented with LSD in 1943 and his subsequent bicycle ride. "This is a day of celebration in the Matrixist community marked by the giving of gifts, bicycle trips, joyful picnics, and other festive activities."
This day marks the anniversary of the deaths of John F. Kennedy, C.S. Lewis, and Aldous Huxley (coincidentally or not, all three on the same day in 1963). Also on this day, in 1977, the first three nodes of ARPANet (what would become the Internet) were connected.