Over the Hill, All Downhill from Here?

I turn 40 today,  I'm staying at a nice lodge about an hour and half from home with some friends that we go with every year on Presidents weekend.  I'm having fun, but looking around I wonder if things will ever be the same.  Here are these people, some close friends, some acquaintances going about their business as if nothing is different.   Only a few know of my situation, still I wonder how everyone can be having so much fun when I have this tumor in my head.  By now I've seen my MRI, the tumor is only 5mm x 7mm, about the size of a jelly belly jelly bean.  Yeah, its classified as small, and statistically likely to grow only 1-2 mm per year, but still.......a brain tumor.

This is not what I wanted for my 40th birthday.