I die therefore I live

The fear that has completely disabled me over the past couple weeks is not of death, but of dying. Getting a terminal diagnosis from a doctor, and sitting on a hospital bed and feeling sorry for myself for the rest of my life.
But wait, we are all terminal. We are all born with an expiration date.
So any doctor would only confirm what I already knew about myself: that I am dying. So is he. 
The best and most powerful realization of this is that my uncertainty is still in tact. Just because I may have a terminal illness, doesn’t mean that is going to be what kills me. Someone could murder me on my deathbed, or infinite other possible deaths. So I am still just as uncertain about my death as I was before. 

I’ve been sitting on this thought for several weeks now. And tonight it hit me: 
Life does not mean death. Death is just a part of life. But death means life. To not be is to say that I once was.
‘I think therefore I am.’ I die therefore I live. 
If you never slept, would you know what consciousness was? Sleep is how we know we are awake. Death is how we know we lived.