A toxic dose of THC is OVER 1,000 times that of an average dose (I read this on a toxicity graph of the most commonly used recreational drugs, including legal ones--the legal ones were very low on the graph, meaning it doesn't take much to overdose on them). So, for instance, one bowl is average, or maybe one joint, or two (depends on tolerance too!). So you'd technically have to smoke OVER 1,000 average-sized bowls/joints/blunts/whatever of high quality Cannabis in a very short period. Pretty impossible, and in more than one way. Not only would most people not have the money to do this, but also one would probably pass out before they could finish 10 bowls. If not, one would die from smoke inhalation first.