The Cookie Test

A few days ago, my co-worker Linda brought in a box of Peak Frean assorted cookies to share with others in the office. I snarfed up a couple of favourites, the Garden Creams, and others dove into the Fruit Creams and the Bourbons. The only ones left were a couple of round ones (whose name I don't know, alas). Linda offered them to me to finish off.
"No thanks," I said, "I don't like those kind."
She stared at me blankly. "What do you mean? They're all the same."
"No, they're not," I replied. "Those round ones are sort of lemony and I don't like them as much as the others."
"But they're all the same," she insisted.
"Well, you'll just have to get some more and we'll do a taste test."
The next day, she brought in another box and crumbled up some cookies and fed them to me. (Your tax dollars at work.)
"That's my favourite, the Garden Cream," I said as I munched the first sample. Next came "the Fruit Cream. You didn't put any of the fruit filling in the sample so I can't tell you which flavour of Fruit Cream it is. But it's clearly a Fruit Cream."
Finally was the "round lemony one that I don't like."
Linda was amazed. "I can't believe it. No hesitation at all. Dead on everytime. Wow. I'm in awe. I thought for sure they were all the same. Well, here, I guess you better finish off the rest of those cookies that I took the samples from."
Once again, science called and I responded in triumph. It was certainly not a cheap ploy on my behalf to get more cookies.
Nosiree.