Flashbacks are common myths.

You're an idiot. Flashbacks are not a real thing. Pretty much every negative effect of LSD is exaggerated or based on biased reports by the government to justify making anything that gets you high illegal. An LSD 'flashback' is more like deja vu, like "Wow this is really similar to something I've experienced before", not like you just randomly go back into a full on trip. If you're schizophrenic you probably shouldn't take LSD, sure. But if you have heart palpitations you probably shouldn't drink Red Bull. People should be responsible for their own decisions, not you or the government or anyone else.