World Pasta Day was first celebrated as part of the World Pasta Congress on October 25 in 1998.
Pasta is a very old dish. Since humans learned to eat wheat, then grind the wheat, make it knead-able and throw it into water to boil, we had a sort of pasta.
How we ever got that idea is most easy to explain with the conclusion that the Flying Spaghetti Monster taught us to do this. This way we can feel the touch of his noodly appendages warming us from the inside.