You should not ride the metro.... because you may run into a Dennis Hopper
Thus generating terrifying memories that Waterworld was created, causing you to panic and ram a train through a wall magically causing it to take flight.
People in shock of the horrors you had to go through... Whoa..
You should not ride the metro because you have NO idea what that sticky stuff is on the seats. And you don't want to know who has been licking the windows!!