Smoking

[Ravenshire]

That's not necessarily true.  I was in the hospital once and wasn't allowed outside for a few weeks.  When I finally was, I lit up.  It floored me.  I was dizzy and felt like throwing up.

I don't know... might not have been the nicotine though - personally I doubt it was; after 48 hours it's out of your system and the feeling is completely different. For instance could you imagine smoking some dry leaves or paper? that too would make you feel dizzy and feel like throwing up, and is in effect no different that what you are doing when you're having a cigarette, but somehow... when you're addicted... the nicotine disguises the sheer amount of smoke you're imhaling, which in any other situation would make you feel completely nauseous.

After 48 hours it's out of your system, but your tolerance for it hasn't changed. The longer you go without, the less tolerance you'll have.