Originally Posted by
LondonElite
Not to belabour the point, but a Canadian entering Canada doesn't need to play this game. The CBSA does not have the authority to stop him coming into Canada. All he needs to say is "I'm here!" (I'm leaving aside customs issues and instances where the person has a long list of outstanding arrest warrants, though even in those cases the Canadian must be admitted into Canada.)
It would not, however, be inappropriate to ask about the purpose of the travel to
other locations and places visited. The answers, even when known to border officials, are often used to determine the level of inspection for customs as opposed to immigration purposes.
Few countries would permit their border officials to deny entry to an individual who presents proof of nationality and refuses to say anything more. But, most can make the rest of the entry experience a thoroughly unpleasant experience if they wish.