Census Challenge

After completing the A to Z Blog Challenge, I began training as a Census Enumerator. Thought the job would be a snap. After four days of "how to do it the government way" I was presented with two binders of addresses and a huge stack of forms.
Now remember, all census information is confidential for 72 years, so I was fingerprinted, and sworn in. That said...
It's been a real challenge trying to find streets that I didn't know existed and house numbers that are obscured by bushes or are non-existant. We won't mention dogs or the oppressive heat.
Some houses are obviously vacant; piles of newspapers, phonebooks and trash. But was the house vacant on April 1? Only the neighbors might know, but the neighbors are hiding inside or are vague with answers.
Ahaa, I hear a TV and it's 5:30 p.m. Why won't someone answer the door? Must be kids home from school with orders to stay inside and not talk to strangers. But am I strange? I have my badge, and official briefcase.
So I leave notices taped to the door with a polite "please call me" ASAP and my cell number and time to call. Do I receive calls? NO. Unless you want to count the person that called after I collapsed for the night.
Seriously though, the residents I've talked to have been very polite and helpful. The only objections I've gotten have been from persons who say they mailed in the form. I hope they are telling the truth.
One elderly grandmother pulled out plastic lawn chairs for both of us to sit on her porch in the shade while she tried to remember the ages and birthdates of her several grown kids and flock of grandkids that lived with her. I can relate. Please don't ask me the ages and DOB of my 12 kids and 14 or 15 (that I know about) grandkids.
So what I don't understand is this. We received a letter in the mail telling us that the census was coming soon. Then we received the census. Then another letter reminding us to mail in the form. Where were all these people? But hey, without them, I wouldn't have this job and earning gas money for my trip to Alaska.