Why does Chinese food always smell so much better than it tastes?

Some person(s) at my office today ordered Chinese food from I assume one of the numerous restaurants in the Southcenter area that deliver. Once the food arrived, the delicious smell permeated every corner of our office floor literally making my mouth water. The smell of garlic deliciousness is almost too much to handle.
But here's the deal - if I actually take the time to order chinese food of my own I know I'll be disappointed as I almost always am when eating Chinese food.

Which a couple of rare exceptions, I've really never had Chinese food that I would consider great. I am almost ALWAYS let down by the flat taste of dishes that smell heavenly. Why doesn't that amazing aroma translate into taste? Does the flavor of the food evaporate in the steam rising off of it?

Inquiring minds...

I guess I'll go try to appease my hunger with a sandwich. Boring, but at least there won't be any high expectations that it won't live up to, to worry about.