Old age and treachery will beat youth and skill every time

Taken from here: http://news.ycombinator.com/item?id=467141

I never got around to digging in to the guts of grep to see what makes it so fast, that 'end of the string' match trick is a very nice one.

They guys that came up with that one must have been sitting there being pretty smug and wearing a silly grin. That's one neat hack.