On my last birthday, I made an intention to live to 120. No I’m really not kidding. I fully expect to make it happen. In fact, I’m undershooting there.  Recent researches on ageing estimate the natural lifespan of humans to be 120-150 years old. That’s how many years your body can carry on, without external stressors, like cancer, heart attack, or being hit by a bus. In other words, if you take care of the…