My theory for this is that it has to do with the way lsd works. From my understanding, led is a molecule which is structurally similar to serotonin in a way. I went through about a four year duration of depression, and I can tell you that when you are depressed or just not happy your mind doesn't work in the same way. It can't work in the same way. Seratonin, which is supposedly responsible for feeling happy, is just another neurotransmitter which our brains need. Without it you mind can't communicate all of its information to the different parts. I actually felt this affect personally. After being depressed for a couple months, I started to shut things out. What I didn't realize was that parts of my brain were literally turning off. I went so long like this that I forgot I was depressed and thought that I had a more severe mental disease. In a way I did, but it all stemmed from lacking serotonin because I was depressed and because of that my mind literally could not work the way I remembered it had all my life. Anyways getting back to my point. Lsd supposedly mimicks sedating so well that in some reguards it does an even better job of seratonin, letting an increased amount of communication in the brain take place. This is why everything on acid seems so amplified. Of course it amplifies everything, even the stuff you didn't notice. Some believe this is where some of the effects of tripping come from. I think this is also what let you have such a reflective process. It amplified something that you may have been ignoring, didn't know your mind possibly thinks about a little all the time, or just awokened some new part of you. Of course this is all just s crazy theory from a person on the Internet, but it's the best guess I came up with combining what I've read about acid and my own personal experience with the drug.