Kevin, why did you take so long to fill out the census?
Well, to my understanding you can't lie in a government study, and the census frequently asks me who is living in my house as of April 1st 2010. If I filled the census out earlier in the march I could be sending in misleading information. How do I know that someone won't come and live with me only for the day, or that I won't take in an orphan or March 31st?
So today, I realized the date, looked around my apparent, and quietly said to myself "nope, just me." got the form and filled it out.