Locked Overnight in a Used Book Store

What would you do if you were accidentally locked in a used book store overnight? If your cellphone died and you couldn't call anyone to rescue you, so you had to resign yourself to the fact that this is where you'd be spending the next 12 to 14 hours.

How long would it take from the moment you realized the above, to start prowling the aisles of the bookstore?

How elated would you be once you fully comprehended the fact that you had the ENTIRE bookstore to yourself for at least 12 full hours (and ascertained that there was a kitchen or breakroom with snacks and drinks to sustain life) with absolutely NO chance anyone would know it 'til someone opened place the next morning?