A slew of apps promise to encourage "lucid dreaming". So why is there such enthusiasm around the idea of controlling dreams, asks Sam Judah.
"You're only bound by gravity if you believe in it," says Rory Mac Sweeney, impatiently.
He is explaining the logic of a dream world which he not only visits each night, but apparently has active control over, flying at will through lush forests or launching himself upward into the night sky.
It sounds implausible, but the phenomenon is known as lucid dreaming.
-Readability/BBC
