9 reasons, since the Classic Sudoku is themed with 9 digits :-)1. Keeps your brain alive and active, a useful break from your usual routine.2. Develops some logical thinking and patterns.3. Helps in improving your patience and concentration.4. Improves sharpness and strategy while approaching and solving problems since you need to be accurate while putting digits and aware of the placement of other digits.

5. Enables you to learn, improve and compete against yourself (based on solving times), thus enhancing your skill-sets and competitive spirit.6. Gives you a sense of accomplishment on completing the grid within few minutes.7. It can build your interest in the world of grid-based puzzles, and sudoku competitions, locally, nationally, or globally.8. It is one of the simplest sports/games/activities to learn, enjoy, play/solve, and even teach.

And finally,9. It is something you can pursue lifelong since it does not have any age limit or materialistic requirements, except paper-pencil.