I used to smoke a bit (about an 8th a week) but have cut back and damn near stopped in the last year or so. I think I've been through an 8th in the last 4-5 months. I feel like I am a lot more productive and I'm able to stay focused. I stay busy and don't even think about it. The best part is my tolerance is insanely low now. One hit and I'm good for the night.
