Everyone in my family used to say that my great uncle would live forever. He was probably the most health conscious person you would ever meet. Once my mom offered him a donut and he said, "I might as well eat poison." Everyday he'd go swimming at a local community college's indoor pool and grew his own produce. About two months ago, he was diagnosed with cancer and was given two weeks to live. Last night he died. He was ninety. He didn't live forever.
This all reminds me that we, as humans, aren't invincible. We're all dying slowly from the moment we come into existence. At any given moment it could all come to an end. We aren't going to be here forever; it's all just temporary.