I'm a little skeptical of the claim that you can't overdose on them (overdose in the sense of using them too much, not lethal overdose). Anecdotally I had a friend in high school who was a brilliant programmer and started using LSD and other psychedelics.
He started posting tons of strange, nonsensical pseudo-spiritual ramblings on facebook and after a few years of this, it became clear he wasn't even the same person anymore - the drugs permanently changed him.
To be fair I don't know if he was using other drugs in conjunction with psychedelics but my (possibly ignorant) gut feeling is to be wary of implications of harmlessness when it comes to any drug.
He started posting tons of strange, nonsensical pseudo-spiritual ramblings on facebook and after a few years of this, it became clear he wasn't even the same person anymore - the drugs permanently changed him.
To be fair I don't know if he was using other drugs in conjunction with psychedelics but my (possibly ignorant) gut feeling is to be wary of implications of harmlessness when it comes to any drug.