They read.

Experts agree that reading is the very last thing most successful people do before going to sleep —President Barack Obama and Bill Gates are known to read for at least a half hour before bed.

Michael Kerr, an international business speaker and author of "You Can't Be Serious! Putting Humor to Work," says he knows numerous business leaders who block off time just before bed for reading, going so far as to schedule it as a "non-negotiable item" on their calendar.

"This isn't necessarily reserved just for business reading or inspirational reading. Many successful people find value in being browsers of information from a variety of sources, believing it helps fuel greater creativity and passion in their lives," he says.