[mattbessey]

Not to mention that it doesn't take a genius to see that a solid object folded in half is not going to be less than twice as thick!

[yiyus]

That's precisely why I immediately thought of "nearly" meaning a bit more instead of a bit less.

It is still no clear to me what makes "nearly" in this particular case to mean "less than". Curiously enough, "nearly crossed the finish line" indeed sounds totally wrong to me.