Couldn't agree more there, I used to smoke weed - well hash - but gave it up a few years ago. I've stayed off it so long because I noticed that my productivitey went through the roof especially as far as writing goes. Also, in general it wasn't doing me any favours anymore.
Yeah, when writing, I always try to sprinkle some humour in. It's tough to appeal to everyone so there isn't much point in trying. I tend to do what I like, and that's about it and is probably the best way to stay motivated to create.
I think the attitude of, "I'm doing this for me, not you," is important for anyone who's creating stuff.