On blacklights
I can't remember the first time I saw my first blacklights, but they soon became a widely seen experience in my youth. Every nightclub had to have them, of course. They were part of the strobe light show experience. When they didn't have spotlights going all over you in red, blue, green, yellow, and purple, it'd be a blacklight making everyone in white t-shirts or white slacks standing out and glow in the dark. And of course I had psychedelic posters hanging up in my bedroom which you could only appreciate by turning out the regular lights and turning on a blacklight. Some people, so I've heard, liked that effect when they alter their consciousness. The effect on your eyes can be trippy.