I offer some of the highlights of my personal experience with LSD, anonymously, due to the very unfortunate stigma. I'm very positive on its ability to unlock potential, trigger insights, expand perspective, and facilitate learning, even in spite of having experienced a few bad trips. Although the experience is deeply personal, I'll try to offer the most concrete accounts I can.
First, of all the hundreds of little insights, interesting trains of thought, and connections made between previously unrelated ideas, there is one revelation in particular that floats to the top of my mind. It's this: LSD confronts you, in an extremely visceral way, with the fact that the entire universe that you perceive and interact with, the whole world and everybody in it, is entirely in your own mind at all times. Sure, it's perfectly reasonable to believe that it's all derived from an objective, external world - but you've never interacted directly with that one, and in fact you can't.
Now, you might say that you already "know" this, philosophically. You can even do the smug, Internet know-it-all thing and say this is completely pedestrian, name-drop Descartes and a bunch of other philosophers, and hit me with a zinger about how this is about as deep as "The Matrix". But I'm not claiming that LSD leads you to the philosophical idea; I'm saying that it slaps you right in the face with it, viscerally. It doesn't tell you, so that you have to think about it in the abstract; it shows you, literally with your own eyes. It's the difference between knowing what the Grand Canyon looks like from pictures, and standing on the edge of it.
It is very common for people to describe the onset of their first trip in terms of waking up, for the first time, ever. I'd describe it this way, too. It feels like waking up for the first time, and realizing that you'd been dreaming your whole life. Of course, this is really just an analogy, and it's more than just a feeling. It's a sudden shift in your actual perceptual processes, which are largely chemical, and have now been altered. But by the mere fact of them being altered, you realize that the default way of perceiving is just that - just a default. It isn't more "true" or more "real" - it's a default, it's massively culturally constructed, and it's characterized by a certain amount of non-questioning of assumptions. What's a color? What's a country? What's a "week"? What's a leader? What is solid? Which way is up? What's a job? Your brain starts trying to decompose every concept into basic principles, and you realize that for a lot of things in the human world, there are none. Just made-up, widespread beliefs that cause lots of people to act as-if, and in so doing, make them "real". Again, there is a difference between merely realizing this philosophically, and being transported outside of the web of culturally-reinforced beliefs and observing it from the outside.
So there's a lot of shedding of constructed concepts. What's left when all that chaff blows away? Whatever it is, it a) seems a lot more real, and b) is obscured in normal consciousness. I'm not suggesting that it would be desirable to permanently lose the ability to think on the level of appointments, check-writing, stop-lights, prospectuses, and the rest of the "mundane". I am definitely suggesting that what is left of experience after all that is obliterated from consciousness is worth seeing. There are parallels here with Buddhism and enlightenment traditions. It's also extremely common for people to offer meditation as a substitute. It's perfectly fine if you don't want to do illegal drugs - hardly anyone will fault you. But don't fool yourself that you're getting the same effect. I've practiced meditation too, and while it does alter consciousness, there are many meaningfully different altered states - they are in no way equivalent or substitutable. (Think about it - if you can simulate an LSD trip by meditating, do you simulate a K trip by meditating differently? Can you meditate yourself to a heroin high by a different technique? LSD isn't just another interchangeable "enlightened" state - they're all specific in their sets of effects. I have no doubt that I too have missed out on plenty of profound experiences by not taking, doing, seeing, or achieving any number of things. It's a big world.)
Sadly, this is turning into a wall of text, and I could still go on for the rest of the day. So, I'm going to force myself to wrap up with just a few more short highlights:
* I learned OpenGL while tripping. The subjective experience was of the information slipping into my brain effortlessly. Normally, I have to read sentences and paragraphs multiple times for them to "sink in". That time, I just skimmed, and understood. The next day, sober, I wrote a couple of neat height-field/terrain programs in OpenGL. Of course we've all learned dozens of even more complicated topics without any drugs, so this anecdote is meaningless, right? All I'm talking about is what it felt like to learn it. It felt effortless by comparison to the way I normally learn. Placebo? Selective memory? Your other favorite bias? Might be interesting to know definitively - but I still had a really good time that night.
* I once won a game of Mastermind on the first turn, without making any other guesses. This seriously freaked out the other people at the table. I wasn't tripping at the time, but I was in a distinctly "trippy" mentality - so much so that I was having a mini-flashback by the end of the turn. What I had done was to realize that the room was a closed system, containing the information about the winning pattern, and that as part of that system, I might have access to the information via other channels. Basically, I just paid very close attention to the other person's body language as I fingered different colored pegs, and allowed him to inadvertently "tell" me the correct colors and order.
* I once did a drawing of a woman from the neck up, while tripping. When I started drawing her hair, I got lost. I was drawing hair for what seemed like hours. I was hiding dozens of other, nested, drawings inside the texture of the hair. It still looked more or less like hair, but if you really looked at it, it was teeming with a whole bunch of unrelated drawings. Sure, I could do the same thing now, but it had never before occurred to me to try that. There is something about tripping that is inherently amenable to that kind of recursive, fractal thinking.
In short, don't knock subjective experiences. The enjoyment of music is a subjective experience, is it not?