Whitey's right on this one, gents.
Read my post with the subject "Question for matintin" for more info (same board).
As for the "profession" question, if you are a Canadian citizen, it's really none of their business. You can refuse to answer. They'll reply that you have a duty to answer all questions under the Customs Act (ask them which section, just to see if it'll stump them). You'll reply that you'll answer any questions with regard to the goods you are importing, but none that infringe upon your privacy. Furthermore, if they really want to know what your profession is, tell them to call up their friends in Taxation and ask them.
Of course, don't expect a smooth secondary.
Oh, and as far as I know, Customs doesn't keep integrated records on departure/return. Canadians have a right to enter/leave Canada at any time. It's just their goods don't have the same rights.
People, you can expect these sorts of questions when you return from countries that are known to be "source" countries for....?