You'd become bland, too, if you just sat on the shelf for months! You'd be glad if someone lit a fire under your seed casing. Spices lose their potency from the moment they go into the jar. The best way to bring out the most flavor and aroma in them is to “wake them up” with a light toasting. Usually, this simply enhances the power of the spice, so you get more flavor from less spice. Sometimes, as in the case of cumin and anise, it gives the spice a roundness and new dimension that the spice never would have had without toasting.

For best flavor, buy spices in the most whole form you can find, whether it's seeds, like cumin, coriander, and anise; nuts, like nutmeg; or bark, like cinnamon sticks. I keep a small electric coffee grinder for grinding spices. Natural oils in spices are what give them flavor. These oils evaporate and dissipate with exposure to air. They remain much more intact inside the whole seeds, nuts, roots, or bark, and are unlocked by toasting and grinding. Even powdered spices can benefit greatly from a light toasting. The method is simple:

Sprinkle the spice into a small dry skillet, and heat it over a medium flame until the spice's aroma comes forth. If you're using a powdered spice, that's all you need to do. Go ahead and use the spice from there. For whole spices, you may choose to grind them after toasting. Usually, you don't seek to brown the spices at all, and you never want to turn any part of them black. But certain dishes call for lightly browned spices, which attain a greater degree of flavor complexity.