If you could know about one event in the future...

[Blaster]

[Anti]

I remember seeing in a comic (2000AD, I'm sure it was) where this Celtic warrior-guy was told by the druids or somesuch hippy on the eve of a battle that he'd die in three days time.
"Bummer" he said...
"No, dude, totally cool, 'cos you'll be invincible in the battle" quoth the tree-hugger.
"Righteous" said the warrior.
So, he kicks a lot of ass on the battlefield, killing left and right, none can stand in his way. His own troops are bouyed by the fact he can't be killed in this battle.
Cue plot twist.
Some random no-mark enemy gets a lucky shot in, spear through the vitals. Seeing this, his own troops do a runner, cos the prophecy is proved false.
Except it isn't, cos the guy takes three freaking days to die in total agony of his stomach wound. Ouchee.

I'm sure that this sort of story appears elsewhere, but my frame of reference is comic books. Comiiiiics!!!