Or rather - what does it mean to be a Canadian?
Most of the nations of the world today were born out of either the ashes of conflict (for example, much of the Middle East after WW I) or revolution (e.g. the United States).
Canada was negotiated. The spirit of compromise resulted in the 1867 BNA act that created Canada as a discrete nation on the world map. Quite literally, Canada came into existance by agreement.
For Canadians, this creates a unique situation in the world. We cannot say that our nation was born out of an uprising to throw off the shackles of past masters; nor can we point to world events around us as defining moments in our emergence. Hence, it is very difficult indeed to articulate just what is Canada - or more specifically, what is a Canadian? - A reality that tends to seriously annoy neo-conservatives and others who seemingly admire the United States for its clarity of identity.
The fact is that the 1867 Constitution is fundamentally relativistic. It seeks to find a balance between a number of conflicting tensions of the day, and in doing so has very much set the tone for Canada ever since.
Look around the world stage at the role Canada plays - Canada seems to consistently wind up playing the role of moderator - like the electrons that jump between the orbits of various molecules, we constantly seek balance.
Essentially, Canada is inherently a creature of relativism. Our very legal foundations are quite relativistic, and the 1983 Constitution reflects that same issue in the domain of human and civil rights.
As a result, Canada winds up being the society that everyone sees aspects of themselves in, but nobody understands. We ultimately have defined ourselves by adopting the good bits from a plethora of sources. Does that make Canada undefined? No - merely difficult to articulate, rather like Einstein's Theory of Relativity - a simple concept, but damned difficult to understand the first time.