That depends...
Am I the only one who knows? Or is the entire population of the planet faced with this same question simultaneously?
If I am the only one who knows, as if entrusted with it, how do I explain my sudden arrival to people I need to see one last time? ...because that's what I'd do, given enough notice.
Then, given enough notice, I'd return home to be with my sweetie for the finale.
.
.
If everybody knows, all bets are off. Hunker down and survive the riots, or not, 'cause the End is Near.
Pushing thru the market square, so many mothers sighing
News had just come over, we had five years left to cry in
News guy wept and told us, earth was really dying
Cried so much his face was wet, then I knew he was not lying
I heard telephones, opera house, favourite melodies
I saw boys, toys, electric irons and TVs
My brain hurt like a warehouse, it had no room to spare
I had to cram so many things to store everything in there
And all the fat-skinny people, and all the tall-short people
And all the nobody people, and all the somebody people
I never thought I'd need so many people...David Bowie, "Five Years"
