If anything, I am proof of how resilient (is that the right word?) the human body is. I smoke and drink, HEAVILY, and have for at least 20 years. I have probably done less than 5 hours of exercise in MY ENTIRE LIFE. I eat whatever I want, when I want. I weigh 220 pounds, but, when you take in the amount of food I eat plus my level of inactivity, I truly do not understand how I'm not at least 800 or so pounds. If I had to estimate, I'd say I only burn about 100 calories from physical activity a day. It is not uncommon for me to take less than twenty steps a day. I vomit up blood-covered "stuff" on a fairly regular basis. I abuse prescription and over-the-counter painkillers/sleeping pills as if they were candy, with no thought going to the dosage limits. I do not know how my lungs, liver, and kidney are still functioning. With the amount of social isolation and lack of mental stimulation I have, I should be absolutely insane. I don't know how I'm still functioning at all.