I've had several experiences with individuals who were faced with the brutal honesty of the end of their lives.
The impermanence of life is something that the vast majority of us pretend doesn't exist until we are forced to face it.
Watching my friend struggle with knowing that at best he might have a few more years to live, is humbling. It reminds me of the impermanence of my own life, and helps me to be more grateful for my friends and loved ones, as it does for him as well.