What should you do with knowledge?

It's definite. My leg will be amputated soon, maybe within a month. I won't be eligible for a prosthesis because the cut will be too high so I'll be on crutches for the rest of my life. It's awful, being on crutches. And even once the leg's amputated, my chances of living longer than a year or so are just thirty percent at best.

A newsboy selling an extra edition of a newspaper.

I'm writing this on December 20, nearly the day with the least amount of daylight out of the year in the northern hemisphere, and I've been busy the whole day. Into the city by train early in the morning for the bad news from one doctor who said another doctor should probably be consulted about it and arranged for that to happen later in the day. I was in no mood to hang out in the city all day, so I took the train home, did a few household chores, then took the train back to the city. It's a forty-five minute ride each way.
I got the bad news from the other doctor, with more explanation, then took the train back home in the dark.
I have no one in my life except two older brothers and a handful of friends. I will tell his brothers, who live nearby, after the holidays, knowing that there's little point in telling them sooner and casting a pall over a family gathering on Christmas Day. 
I have, however, a funny compulsion to spread the news. Part of this may be because he wants the attention and the sympathy—pathetic, you're right—but another part is simply the human impulse to tell people things you know and they don't, especially when you're sure the information will provoke a strong response. "Guess who died?" people say with a wide-eyed grin when a celebrity dies. That sort of impulse.