This actually* (*should have) happened on the set of LUCY:

MORGAN FREEMAN: It has been estimated that human beings only use 100% of their brains.

LUC BESSON: CUT! Mister Freeman, it says 10%.

MF: But… that’s ridiculous. Nobody still believes that.

LB: The script says 10%.

MF: I’m not sure I can sell that line. I rather doubt anyone can sell that line. Perhaps 90%, but ten?

LB: How’s this? Your pay goes up by 10% for every 10% below 100% you’re able to sell me.

MF: …

LB: I’m serious.

MORGAN FREEMAN: It has been estimated, and subsequently proven through rigorous experimentation, that human beings use NEGATIVE ONE THOUSAND PERCENT of their brains…

(By Howard Tayler, originally posted to Facebook. Now it has a permanent home.)