Psychic Kids

On my shopping trip today, I got the truck filled up. An hour after I get home, James needs to borrow it. How does he know??? When they're little, you can get chores done while they play. No problem. But close the bathroom door and they're pounding on it within 30 seconds. When they're grown, they only need to borrow your vehicle right after you fill it up. So...how do they know???