My grandfather always taught me that this pertained to boredom. Especially is children. If you are bored, you are like an inquisitive, curious cat and that, as we all know, leads to trouble.
Apparently, according to superstition, the devil is constantly on the lookout for bored minds. He wants to give these people some mischief to get into. Eve was bored and strolling around the garden of Eden and she ran into the devil who taught her to try new things. Like, "try this juicy fruit, you'll love it!" Eve was tired of idly ingesting all of the other food around, so she jumped at the idea of trying something new and "naughty".
Cats are like that too. They idle around all day, sleeping 18 out of 24 hours, then the devil just gets into them and they try walking across my keyboard or jumping into empty boxes and such. They are up to no good, I tell ya.