Some Odd questions from Canadian Customs

I've often found it interesting just how much they already seem to know when they start talking to you. You get the normal question about ever having had a DUI, why and where you're traveling, lots about firearms etc. My wife however has never been asked if she's ever been fingerprinted, they always seem to ask me the question, which I have as a result of military service. They've also twice asked me how many passports I have, but never asked my wife the same question. She only has a blue one whereas I have the blue and a red one for work related travel.