You are wrong. I know my own experiences perfectly well, and that statement is just not right. While I'm sure there are a variety of experiences that can be collectively labelled as "flashbacks", I can vouch firsthand that flashbacks can be EXACTLY like the "distorted propaganda".
Yeah I can say firsthand that flashbacks can be way way way more intense than just seeing something wiggle or something. I'm not going to say that it's exactly like tripping again, but it's pretty dang close. Depending on what you count, I've probably have 3-4 full blown flashbacks (this is after tripping on acid once, mind you), and all but one occurred when I was really high, but it was NOT like your usual high - out of body type feelings, etc. etc. Now, I am really sensitive to pot, so, it's tough to know if it was a true flashback, or if after tripping I am just more sensitive than ever to the time-distortion and out of body effects of grass. The morning after one of these flashbacks, I was in the shower, sober, and I experienced intense depersonalization and the feeling I was leaving my body. It was crazy. Not something I'd wish on anyone. So yeah, don't take it lightly. It's unlikely you're going to be driving down the street and launch into a 600 microgram style trip, but if someone told me that had happened to them, I would believe it.
I have taken both and had very good trips on each but the difference for me is that when you eat shrooms and you reach your peak your gradualy ride out the trip but on lsd right when you think the trip is slowing down itll kick back in again.
Someone mentioned they were sensitive to pot, in all likelyhood you are also sensitive to other drugs as well, could contribute to the experiences you've had. I feel as though I may have tread a different path - on doses that totally spaced out one of my friends, got visuals stuck in front of his face to where he couldn't see, I was merely up in abstract-thinking-land, having the time of my life. Some of the depersonalization feelings that some of you mention I've felt many, many times over the course of my life, starting before I really recall a whole lot of my other experiences. I seem to be quite a bit less affected by these types of drugs - even when I ate around 15 grams of mushrooms I never totally left this realm...though I was quite "out there" for a while. When I took the tenstrip of good acid, the only cool visuals that happened were my closed eye visuals, and what I saw turned out to be a predictive vision of the next few months. But I've never experienced anything I can really attribute to drugs...there were a few times where I felt like I was being kicked back into a trip, but that was after smoking pot so it wasn't a problem at all. The type of flashbacks some of you talk about put you in a very small portion of drug users, most people never notice anything wrong afterwards. A few of my friends that have tripped don't even know about after-effects and so all they ever talk about was how great the experience was and how they want to do it again. It's a risk you take, it's not like taking acid is "safe" in the first place.