Recently, a genealogy site has begun to make parts of the British 1939 census details available for a price.
Fortunately, being a subscriber meant I received a discount code which opened a record of my choice at a much reduced price. But, some parts are still blacked out unless that person died before 1991.
This means I have to do some guesswork. My memory tells me that during WWII (1939-1945) my grandparents had a lodger. I have no idea apart from the lodger being male. Looking at the street it appears that other houses have an extra person that's not part of the family.
There's no record of whoever lived at no. 1. Yet, I knew the people living there and that they'd been in the house since new.
Whilst the discount of 50% was applicable (one record) I've opened some more to read and to save.