Reading

I have a simple yet incredibly time-consuming question: what posses somebody(in particular me) to spontaneously decide some morning(this morning) to pick up Harry Potter and the Chamber of Secrets and finish reading it by six o'clock the same evening?  I am actually very curious what makes those books so good that I would do little else but read them, even if it is for the forth time(the same actually goes for a variety of other written works).  Any insights would be greatly appreciated.