"------ and contributes to a host of medical maladies in adults. That fact alone should give you and everyone else pause to consider its unhealthy aspects."
Because of your genetic profile the wear and tear theory doesn't apply to you...and I am happy for you. But...most people are not like you and smoking does harm them.
Ever visit a Veteran's Hospital and check in the cancer ward? I have.
http://www.infoaging.org/b-the-4-random.html
Here is one more source about the tobacco and cancer link, but it probably doesn't apply to you again because of your genetic profile...
http://www.oralcancerfoundation.org/tobacco/index.htm