Comparing nicotine to bubble gum or exercise is a little extreme, considering nicotine is just as addictive as .......
I don't mean to start an argument, and I mean this sincerely.
The difference between caffeine and nicotine, is that nicotine is usually inhaled, while caffeine is ingested. There is enough nicotine to in one cigarette to kill you, but the amount weakens in the process of smoking or vaping.
It is as dangerous as pure potassium cyanide. (
http://www.e-cigarette-forum.com/forum/announcements-rules/144783-warning-e-liquid-diy-safety.html)
192mg of pure caffeine can kill you but it depends on how much you ingest in a certain time frame.
40-50mg of nicotine can kill you
I know that if you ingest a bottle of nic juice you would probably die, and if your hands come in contact with pure 100% nicotine it can seep into your skin and kill you. The same may be said for caffeine, but at a much lower dose.
http://www.e-cigarette-forum.com/forum/diy-e-liquid/1783-read-first.html
See the problem is I love nicotine because of it's stress-relieving qualities and it's effect to "calm the nerves", but the fact it's so toxic and addictive makes it harder to fully commit to the "potential" benefits.
The toxicity is not the real problem with me because I'm not going to be drinking nicotine lol, but the addiction aspect still kinda bugs me. I started e-cigs not to break the addiction of nicotine, but to find a safer alternative. I hope to eventually ween myself down to 0% nic juice and be totally free from the toxicity of cigarettes and addiction. But for some reason it's taking me a long time to do that.... hmm... I wonder why lol
Also the definition of "addiction" is kinda blurry, but I'm basing my definition on my experiences and the countless people I know who "need" cigarettes or they go insane or get "stressed" (which I think might be a withdrawal symptom.)