FOR SHARPENING HOOKS (IN THE EVENT YOU DON'T WANT TO MISS FISH)

Fact: you're more likely to cut yourself with a dull knife. Another Fact: you're more likely to miss fish with a dull hook. Think about it: your fly has a ton of opportunities to become dulled, even if the hook was sharp when it left the manufacturer. Why not put your fly in the best condition to catch fish by sharpening it?

Look at it another way: control the things you can control. You can't control the weather or the water clarity, but you can control if you're fishing a sharp hook. Sharpen your hook. Catch fish.