When I was nineteen, I went to a party, took some LSD and walked out into the moonlit Arizona desert. I needed to be alone and needed to find something, although I didn’t know what. I climbed up a small mountain to a view of the city skyline. The climb apparently winded me, because my heart was beating fast. My pounding heart caused me to be increasingly aware of my mortality, which caused my heart to pound even faster. I wondered whether the combination of a psychedelic and physical exertion could kill me. My heart raced faster. And then I died.