Wikipediaed!The papillae in different regions of the tongue have distinctive shapes and characteristic numbers of taste buds associated with them. Scattered over the main body of the tongue are approximately 200, small, mushroom-shaped (fungiform) papillae, which have, on average, only three taste buds each. Larger (foliate) papillae are found at the back and sides of the tongue. They consist of up to nine folds of epithelium and have as many as 600 taste buds each. Eight to 12 larger mushroom shaped (circumvallate) papillae, each surrounded by a circular trough, lie at the back of the tongue in a V-shaped formation; these have on average 250 taste buds each. Scattered taste buds are also found in the epithelium of the soft palate, pharynx, larynx and epiglottis.
Your tongue is only a portion of your taste/smell system. As this excerpt demonstrates, the tongue has taste buds in various areas of the tongue. I'm assuming you don't normally burn your
whole tongue. Or do you?
Remember that people have various degrees of sensory reception. Some are better at seeing than others. The same goes for the other senses. For example, my sense of taste and smell are great. Amazing, actually, which is good because I love food. However, my sense of hearing sucks. Comparatively, Baraka_Gurl has a nearly superhuman sense of hearing, which is good because she's an elementary school teacher. But her sense of smell sucks.
I'm guessing that burning your tongue countless times has done relatively little to your overall ability to taste. The mouth in general tends to have a high rate of healing. Also remember that our senses change as we age. That's why I've been wearing glasses of increasing power since the age of fourteen.