While living in China, I discovered that it was a good idea to rinse tea with hot water before brewing it. The rinse removes a certain rough taste — easy to notice in side-by-side comparisons. A Chinese college student made an interesting analogy:
Entertainment news is like drinking tea, first time is like washing tea leafs, no one really cares. Maybe 2nd or 3rd time it will have the sweet taste, but in the end it gets weaker and weaker.