Why does meat taste bad when you reheat it in the microwave?

If I'm not hungry enough to eat a whole steak or chicken dish at a restaurant, I won't order it because the leftovers will be no good. Cold they taste fine, but if you want to heat up your leftover filet mignon, forget about it. putting it in the microwave destroys the flavor. Why is this? Some people say they don't notice the difference in flavor at all. I don't get it!