Have a friend who's tried shrooms on 3 separate occasions now. As far as they're aware, they've tried ~3g-5g each time, others have seemed to be experiencing effects, but my friend hasn't. They're not on any meds, SSRIs/SSNIs... I haven't been able to find much in the way of discussion about natural immunities to psilocybin or anything... I was expressing that in my own experiences, it's had synesthesia-like effects, and they were expressing that they have just... a sense of synesthesia in their daily-life, and maybe that's why it's not working for 'em. I expressed that it does more than that, etc.

I don't know if the people they've been around are just more placebo-prone or what, but it's an experience they'd like to have, and have been disappointed. Wish I knew what might be preventing 'em from have an experience, or what might enable it.