I always take an interest in these people, despite the fact that I am not descended from them, because I think it's a shame when they are forgotten and because they were a part of my ancestor's lives.
For me, one of these relatives is my 3rd great granduncle, Clinton Rorer. He was 63 when he died, not unattractive, and had been a wealthy and prominent man in the community; a farmer, a sheriff of Montgomery County, PA, a founder of the Chestnut Hill Casino Company, a Freemason, a congress nominee, and a share holder in the Blue Mountain Railroad Company. So he was certainly very far from an "invalid" whose prospects of marriage and children were nil. And it's not like he was the elephant man (see photo below), uglier men have married and had children. He seemingly chose not to marry and therefore never had any known children (he could have had illegitimate children but if that was the case, they have been lost to history as far as I know). Modern minds tends to assume he was homosexual but there are many other possibilities. With all his wealth, he may have felt that he could never be sure that any woman he married was not just after his money and social status. Maybe he was just a romantic who wanted to marry for love but never found it; or maybe he did find it but it was unrequited or maybe she died before they had a chance to marry. Another possibility, though perhaps far-fetched, is suggested in the fact that Clinton’s sister Mary also never married. Could it be there was a secret incestuous relationship between them?
It's certainly a mystery and one that I am forever on the search for more information and insight. Clinton finally succumbed to kidney disease and his wealth went to his two nieces, one of whom was my second great grandmother (who then proceeded to spend, spend, spend with her husband until nothing was left by the time of their deaths for their descendants to inherit - thanks for that!).
It's a shame that such an interesting man has no descendants to remember him and so I've taken special interest in his legacy so that he is not completely forgotten to history. I encourage everyone to do the same with their own "forgotten" relatives - don't overlook them just because they are not your own ancestor.
A part of me feels that if someone is remembered, it somehow makes their life more meaningful. It's sad to think that I myself might be forgotten in time when I either have no living descendants or none of them have taken up an interest in their family history. I suppose that is part of why I do this, because each person in my tree was a real, living person just like me and it saddens me to think that their legacy might be completely lost to time and history, as my own could be. It's frightening to think of how insignificant most of us are in the grand scheme of things that we could be so easily forgotten.
December 31, 1835 - December 12, 1899