I recently gained some photographs as a result of the death of a relative. His father had written on the back of some of them, I suspect not always accurately, while others had unhelpful remarks like "Mary and myself".
It just happened that an old letter from my mum fell out of a family history folder of mine and re-reading it she had speculated that her grandfather might have had a sister in Canada as 'family' there had sent food parcels over during the war. She remembered the surname but not much else. For some unknown reason an old address book had 'escaped' from my archive box, perhaps because I had had thoughts of throwing it out. I thought I knew all the names in it anyway, some from Canada when my dad served there. A quick glance for old times sake, and there was Mum's 'cousin'!
Going through my photo haul I had been trying to group them together by subjects and developer's markings. One group meant absolutely nothing to me. They were marked on the back but they weren't names that I recognised. It suddenly struck me that they were taken at the back of a Canadian house. Using one of the 3D mappings I had a look at the back of the house in the address book. These houses were wider at the front than at the back and the transition was made by a wall at 45 degrees with windows set in it. Checking the suspect photos and there was the 45 degree wall!
Looking at the person identified as "myself" I can see a strong resemblance to my mum's grandmother. Now she had four half-sisters, three ended up buried in Belfast, as to the eldest I don't know, but she looks now to be the Canadian lady.
If my mum hadn't written her letter, my dad hadn't filled in an address book and the photo lady hadn't written some of the relationships on the photos there is a Canadian branch of the family that might have got lost forever, (assuming I can positively identify the 'cousin'). Moral: Write It Down!