It happens. I don't get it but apparently some people don't have any clue how cars work and don't have any interest in learning. Times like these are why you got a car with full warranty and free maintenance
Other than what others have posted, you might want to drive in reverse for a few feet with the handbrake pulled up. According to the owner's manual this 'adjusts' the parking brake so that it functions correctly.
All in all, don't worry about it