„The number is one of the basic mathematical concepts. Numbers developed due to the need to count objects produced by direct, practical activities of humans. While the rational numbers were known in Antiquity, the positive and negative numbers were first used by the Indians, who also introduced the zero." (Meyers Neues Lexikon).
It's as simple as that. And bound by scientific tradition, Shashwati Talukdar tries to impose an order of comparable simplicity on her personal history.