People always make jokes like this about LSD, and granted a lot of "revelations" and "brilliant ideas" turn out to just be drug-induced delusions, but you really can learn a lot about yourself and other things from LSD. A lot of the things you learn are deeply personal and wouldn't be meaningful to anyone else. Some are things you already "knew", but get integrated better from the experience. And a lot of people have profound spiritual experiences, which, truth aside, provide their lives with meaning.
And then there was the experiment where a couple dozen professionals who had been stuck on various problems for months were given LSD to determine it's effects on creative problem solving. (You can read about the experiment here:
http://www.themorningnews.org/...) but here's a quote:
"But here’s the clincher. After their 5HT2A neural receptors simmered down, they remained firm: LSD absolutely had helped them solve their complex, seemingly intractable problems. And the establishment agreed. The 26 men unleashed a slew of widely embraced innovations shortly after their LSD experiences, including a mathematical theorem for NOR gate circuits, a conceptual model of a photon, a linear electron accelerator beam-steering device, a new design for the vibratory microtome, a technical improvement of the magnetic tape recorder, blueprints for a private residency and an arts-and-crafts shopping plaza, and a space probe experiment designed to measure solar properties."
Yeah, LSD is a lot of fun to use recreationaly, and it's easy to mock "the semi-coherent ramblings of some guys on LSD," but LSD has a lot of potential to offer our society if only we'd take it seriously.