Strychnine doesn't get you high it just kills you. Apparently it acts as a stimulant at low doses and would cause seizures and convulsions, but I find it difficult to believe anybody would be buying weed laced with strychnine. The stuff is so toxic and it can be absorbed through the skin, eyes, mouth, inhaled, etc. Any idiot looking to 'lace' the weed they plan on selling with it would very likely wind up in the hospital themselves before they managed to sell a gram.
Phencyclidine is something I could see weed being laced with, rarely, without the knowledge of the buyer. And any other drug that is inexpensive and can be dissolved in an aqueous solution, sprayed on the buds and not destroyed by the high heat of smoking. Otherwise more viable concerns are non-psychoactive adulterants, very fine particles of glass, sand, pesticides, etc.
I remember (barely) some of the first times I got high it was way too intense. I would feel dissociated from my body, like I was in a movie, wondering if I was saying things I was thinking and vice versa, seeing trails, etc. One time I was so high and disoriented I ate an apple and vomited about 30 minutes later... then had to go lay down for a considerable amount of time.
