There's a great first-person article in the Washington Post today written by a man who has very limited senses of smell and taste:

This is what we established on my first visit to the UConn clinic, where I spent two hours smelling bottles of diluted alcohol, trying to identify canned scents, and swishing dozens of liquids around in my mouth to rank them by their taste. The scents were a failure: Of all those placed before me, I could recognize only Vicks VapoRub. Now, that's depressing. Imagine if everything you smelled could only be categorized as either "Vicks" or "not Vicks."(Washington Post)