I can't imagine

We visited a friend of ours last night who has stage 4 metastatic cancer. He seemed to be in good spirits and loved playing with the kids, and we enjoyed the visit too, but I just couldn't help feeling a little sad when we left. His wife sends updates every day or couple days, and I know that things aren't going well and he is in constant pain. I just can't imagine being in either of their places. I can't imagine knowing that my days were numbered like that, but I especially can't imagine watching my husband go through that. And yet, none of us knows how long we will live on this earth or what we will encounter while we are here.... It just brings home the knowledge that we should live every moment as though it were our last....