Why is Minecraft in 16x16 pixels?

I wanted to ask why Minecraft is divided into 16x16 pixels? So I mean without a Resurcepack

Most such "block" games are in this format.
This has many advantages (e.g. In design, etc.)!

It also has that "sandbox" feeling.

I think you can only find out the "exact reasons" through Notch…

Because 8 is half of it and Notch had 8 beers when he came up with the idea for the game.