Being young & still forming/growing never hurt María Sabina
I was & still am curious to see what happens with things if you try them out & push the limits, like as a young youth we tested all limits put on us by "society" & I have always rejected social conditioning, at the time all I ever heard from people was "drugs send you mad" when I found out you didn't go kill your parents after smoking a spliff I was curious to see what happened if you sniffed glue or ate a load of acid.
My view is any drug on a developing mind & body can't be worse for you than the G.M. food or extra rubbish put into our food & water on a daily basis.
Of course I have known a few people to become "ill" from doing to much stuff but as my #1 hero said "Buy the ticket, take the ride"
In my case my use has made me a far more aware person of spirituality, zen buddhism, ESP, NDE's for example.
On a daily basis for a good 5 months I read the Hagakure by Yamamoto Tsunetomo & reflect on the ideas of what it says (If you have seen the film Ghost dog it's the book the quotes come from)
“There is surely nothing other than the single purpose of the present moment. A man's whole life is a succession of moment after moment. There will be nothing else to do, and nothing else to pursue. Live being true to the single purpose of the moment.” ― Yamamoto Tsunetomo, Hagakure: The Book of the Samurai
I have a far more balanced view of life than people who have not done the things I have got into, as a teenager when 99% of people were worried about their Nike clothes, their friday night drunken sex, what their freinds think of their social standing I was thinking about UFO's, ghosts, shaman in Peru etc. I would not have thatview if it was not for the things I had taken, call me a freak if you like btw 
I hope that gives you an idea why I have done what I did 