I am momentarily breaking hiatus specifically to say that you don't even need marijuana or alcohol to suffer from this. The normal human capacity for self-delusion and need for self-esteem are more than deadly enough all by themselves.

Personally, I'm still struggling to accept this lesson: that it's not enough to be a smart person who has good ideas; you need to do something that actually works. It is, in its own way, a highly counterintuitive idea, much like this notion that plausibility isn't enough, and beliefs should actually predict experimental results. I keep wanting to protest that I was morally right. Well, say that I was. In order for that moral rightness to change anything, I still need a method that really actually works, not just morally works.

I think there are legitimate questions about the advisability of marijuana, but this is a claim for which counterexamples are plentiful. Alan Moore springs to mind.

OTOH "you only tell your story once so do it on paper" is also in Dorothea Brandt's "Becoming a Writer".

Funny, I got the same advice sans drugs about NaNoWriMo a while back, and was just passing it on recently to someone else. The way it was put to me, though, was that "you can only tell your story once." Not literally, of course--you can relate what happens in it more than once--but you can only really tell it and put your heart into it once. Don't waste it talking to your friends about the idea. Get it on paper the way you feel it. Then tell your friends the lesser version afterwards, or just wait and let them read what you wrote down.