No, however most people don't brush properly and don't floss or brush their tongues so that is often why they still have bad breath. If it doesn't go away by brushing it's time to see a dentist to see if there isn't any underlying causes or medication or something wrong with your jaw etc.
I wrote a howto about brushing correctly: http://www.funadvice.com/howto/cleanteethproperly
Bad breath could also originate in the lungs or the upper respiratory tract. If you find that brushing and flossing frequently aren't helping, maybe going to your dentist would help narrow down the cause. If you don't have dental insurance, perhaps visiting your general practitioner would help as well.
Well if its constant bad breath thats a sign of another problem like an infection, tooth decay, or gum disease. Other than that to cure occasional bad breath caused by foods or something else, brushing your teeth, using mouth wash, mints and gum, or chewing parsley leaves all can freshen your breath.
you should also brush your tounge as well, as thats were a lot of the bacteria that makes your breath smell bad is. just lightly brush it with the toothbrush
Yes, tooth decay is one major problem where constant bad breath will come as food particles also get stuck in the teeth gap