People frequently tailor their questions to what they think the library can supply.
Or they may ask for an almanac when a publication accessible through the Statistics Canada Catalogue for example might give better information on the statistic they are looking for. Try to be as clear as possible. And if you think they misunderstood, don't hesitate to make sure they didn't. You may be under a lot of pressure or a tight deadline, or have had a bad day. But it doesn't pay to be impolite or brusque with librarians or library workers you've approached to help you.