Have you ever prepared a meal and said this? If so, you may have added the fresh herbs to your dish too soon. Keep in mind that when cooking, it is best to wait until the very end to add the herbs to what you are preparing. If making a stir-fry for example, add them about 1 minute before you pull the wok from the stove. If you are cooking hash browns in the oven, sprinkle the chopped herbs over the potatoes about 2-3 minutes before you pull them out of the oven.
Many people feel that if they add the herbs earlier in the process, their foods will be exploding with flavor. The opposite is true however. If you add them too early, the oils may evaporate or be destroyed by the heat, thus eliminating their taste. When this happens, you may never know you added them at all, except for the green specs of tasteless leaves that are now on your plate.
Of course, there are exceptions to this. If you are using fresh bay leaves, you need to add them at the beginning and allow them to simmer with the food. If you are preparing a beef roast in the crock pot, add a 1-2 fresh bay leaves in the morning and let it cook all day. If you are making a simple syrup or infusing cream with mint, you can let the mint steep for 30-40 minutes to create stronger flavor.
Hopefully these tips will help ensure that your efforts in the kitchen are not without flavor!