Well its very important as you may already know. I had a a few TIA's before my "main event" Most were brought on by stress, some right after lighting up. I was 29 so I had no idea what was going on. It was only after I woke up unable to move my left arm that they did a CAT scan and DXed me with a blockage. Of course I continued to smoke and three days later my left torso and leg went numb. I recovered well and quickly but kept smoking. it seemed just one smoke would set me back a weeks worth of rehab. I finally figured out either keep smoking and lose my left side or quit smoking and be able to walk, and ride ATV's. It was a choice I had to make and it was very easy once I knew I had to make it. 8 years smoke free now :)

Be strong you can't make an addicted man change. Even he can't thats why it's called addiction. To be honest, it is my opinion that it is not your "job" to see that he quits. Its your job to take care of you and learn from peoples lack of judgement.

Hope that helps.