Keanu Reeves played Bart Simpson in Johnny Mnemonic.
A recurring character arc in many roles he has portrayed is one of saving the world , as can be seen in the characters of Ted Logan , Buddha , Neo , Johnny Mnemonic , John Constantine , and Klaatu .	Constantine	Constantine (film)	character arc	character arc	Ted Logan	Bill & Ted's Excellent Adventure	Buddha	Buddha	Neo	Neo (The Matrix)	Johnny Mnemonic	Johnny Mnemonic (film)	John Constantine	John Constantine#Film	Klaatu	Klaatu (The Day the Earth Stood Still)
Keanu Reeves plays the title character , a man with a cybernetic brain implant designed to store information .	Keanu Reeves	Keanu Reeves	cybernetic	cybernetic	brain implant	brain implant
