I've always found the questions asked by Canadian officers to be intrusive, sometimes rude and frequently annoying. It must be a uniquely North American thing.
There have been many instances where I have been very tempted to indeed say" It's none of your business!" but have refrained due to the certain cavity search that would follow.
The form clearly asks what amount of money was spent outside Canada, if you are bringing in any food items, and what quantities of alcohol etc. were purchased abroad.
In this context, I detest being asked "what exactly did I purchase?".... my reply of " nothing illegal, no food, tobacco or alcohol and I did not go over my maximum allowed spend" has always been insufficient.
Thankfully, as I am no longer a Canadian resident, the questions have improved markedly.
And I'm even more grateful that I never have to endure any of these kinds of questions whenever I enter most other countries outside North America.
Somehow most of the world can cope well without knowing if I purchased a jumper and two pairs of socks while in London.
Mcm.