Do you know the feeling when you outsmart an IQ test?

I was tested by a professional, and I got a simple task. I was told a number, and I was supposed to say it in reverse.

After a while, the doctor said:Wow, you're doing REALY great. How do you do it? Do you see the numbers written in your head or something?

She wasn't amused, when I said, that I repeat the series in my head forward, and just saw the last number and repeat again.