Indeed.
To be honest, I've experienced some of the best meditation when I was younger, before smoking
marijuana regularly. That was long ago. Perhaps I was more 'into' it then, I don't know. The odd thing is, the only time I feel like meditating these days is when I'm under the influence of cannabis. I just can't seem to focus or put much energy into it being sober, and I usually fall asleep before accomplishing anything.
When I smoke, though, I have a hard time suppressing my thoughts. It's like a paradox of some kind.