Of all my vasana, cannibis has been one of my strongest. I use to smoke, I used to really enjoy it, and as some have described the heightened sensitivity is very seductive when practicing yoga, it seems that because of the relaxation effect you are able to release more in postures.
I began to do a personal comparison making notes of effects during practice and after the next day. I compared practices with and without, during and after (next day , day after , day after that etc) leaving min 2 weeks gap between smoking and non smoking trials. My personal experience was, although cannibis seemed to enhance my practice, relaxation, feeling of oneness and flexibility while high. The next morning it had the opposite effect, I was stiffer, tenser, duller, because I smoked there was a physical lump of congestion in my chest which effected my breathing. I was emotionally physically , mentally and spiritually duller, and this detrimentally effected my practice the next day. I felt crap compared to the non cannibis weeks. and I became aware how long it took, to get out of my system. I tried eating it instead, to see the effects, very similar but less chest congestion. I had to admit to myself that during non cannibis weeks I felt more clarity, and although I didn't immediately get the instant increased sensitivity and high, what I did experience was more sustainabe, throughout the day, night. My practice physical/emotional /psycological/spiritual was more balanced, (less swings highs/lows). Most practice happens off the mat, so this was important to me. As I did this test I became increasingly uncomfortable with taking cannibis, although the habitual patterns were still strong (associations of sensual and social pleasure, that had actually become habitual and monotinous) , part of me was saying, ahimsa, because I had really felt the harm it was doing me and could not deny its effect any more.
Gradually, I stopped because I relalised it was creating conflict in me, and I could not pretend I was getting any benifits anymore, I had proved to myself that the short term high was very low compared to the benifits of consistent regular straight practice for me. (patanjali 2.16 ) At the end of the day if breath is life/Self I felt I was cutting myself of from it.
5 yrs on with consistant regualr practice I experience increased sensitivity,and awareness more of the time. Life is my practice, I have the pleasure of fully experiencing life challanges and difficulties without the need to dull the pain or stimulate more pleasure. If someone offers me a smoke I haven't taken it, not becuse of any moral issue or even fear I may start again, just becuse I no longer can see the point.
Referring to previous threads yes, attraction to pleasure and eversion to pain has been a big part of this process. But at the end it was ahimsa non harming that cast the die for me, to reach out with tenderness and care to all living things I had to have this same care for myself, the dullness cannibis created in me felt like an obstacle to my desired union with the divine (yes, I'm still working with desire!) . I am gratefull to all experiences, our lives are the path.
This account is totally subjective, and I am not saying that these are the effects cannibis has on anyone else, this was just my experience at that time. It could be argued that it was only when I percieved the effects as negative that it did me any harm, and thus it was approprite to stop. Without my enquirey who knows?
Good luck on the path wherever it takes you, with or without cannibis!