a point about the method of academic reading

you are reading and, suddenly you are faced with the following «(Name, year numer: page(s) number)». What are you supposed to do? Go and read said book? Not go and read said book? Keep on reading what you were reading? If you chose to read the said page(s) of said book of said author... how can you be sure you'll understand what the author meant out of context?

If you decide to keep on reading what you were reading, will you not forget to go and check or, more importantly, will there be a point to go to the (name, year: page) mentioned before? Won't you be reading some other relevant aspect?

I trully do not understand this. I trully fail to even grasp this sort of «academic» reading. Where I came from, you would read (Name A, year: chapter about X) followed by (Name B, year: chapter about X) followed by (Name C, year: chapter about X). And that would be that! It would be annoying. It would be like reading the same thing over and over again... but you knew what you were doing!!

If there is no method to this, must I conclude this is art? And if it is art, should I have not been told in advance?