"I've heard this story countless times... something (usually around age 20) just snaps, and suddenly THC == paranoia." It's common for people to smoke more and

"I've heard this story countless times... something (usually around age 20) just snaps, and suddenly THC == paranoia." It's common for people to smoke more and more cannabis as their tolerance grows, and higher doses of cannabis can easily lead to paranoia and other adverse mental effects. If these people took a long break and then tried the smallest amount of the weakest pot they could get, they might find that they can enjoy it again without getting paranoid.