I've done LSD numerous times, including "heroic" doses, as have many of my friends, starting 30 years ago (I haven't in a while as i no longer feel the need to

I've done LSD numerous times, including "heroic" doses, as have many of my friends, starting 30 years ago (I haven't in a while as i no longer feel the need to blow open those doors). Not one of us has ever had a single flashback, let alone "persistent" flashbacks. If they were ever really an issue, it was long ago with different/absurdly strong formulations.