[nerdponx]

A 10-day silent retreat is really intense though.

A few minutes a day of calming your mind and being still in your body is a lot different.

I suspect the author's 20 minutes a day of meditation was a bit more intense than just that. They describe voraciously reading Zen literature and also describe strong personal Christian beliefs.

And why would you keep meditating intensely every day after you've started experiencing these symptoms? Wouldn't you want to back off a little at that point?

It seems like people "abuse" meditation the same way people abuse hallucinogenic drugs, losing all sense of moderation and going too far with the psychonaut exploration stuff.

Maybe also some people are unusually susceptible to these negative effects, and/or are unusually susceptible to being swept up in the spiritual quest fervor. I think this is the author's thesis, and fine, point taken. Those people in particular need to stay away from intense practice and should probably seek out a guide. But I think the majority of people don't have this problem.