Why are there only 8 PC-boxes?

Question

There are 18 in Gen 4. Why are there less?

Comments

You're right, I even saw a sign when I was running around in the game one day wit the "Trainer Tips" that the number of boxes of the PC has increased to sixteen, yet I still have eight.

Answer 1

When you have at least one pokemon in each box, it increases to 16 boxes. After you defeat the E4, then you get 24 boxes.

Answer 2

Because it starts like that in pokemon black and white and the more pokemon you fill up the more boxes you'll have. Like it has eight then sixteen

Comments

There are 8 boxes before E4, 16 after? COOOOOOL