I've long had this sense, that if I started smoking weed every day, I probably would develop psychosis sooner or later. I feel like my connection to reality is at times somewhat tenuous, and heavy cannabis could easily disturb it enough to break it entirely. I suppose I could be wrong, but that's a hypothesis I'm not going to test.

I do think some people can have that "latent" potential yet have the good fortune of never activating it – and cannabis definitely has the potential to do so (although most recreational drugs probably can given sufficiently heavy long-term use).

(I tried cannabis once, years ago, I could see why people like it but I didn't feel any great urge to repeat the experience – and worries like this also discourage me – which is probably for the best.)