Know what your fish eat

I found a short article at Spring edition of GameOn (Dick's sporting goods' magazine): Brent Postal, "Purge and splurge." It basically discusses how to organize your tackle box. At the end, Postal said,

Nothing beats knowing what food will be available to the fish you're trying to catch. For example, if a smallmouth angler knows grasshoppers will be around, he or she can leave the deep jigs at home.

Bingo! I think it is THE advice to all anglers: "Know what your fish eat!"