There are some family lines I've avoided researching. Take my husband's 3x great-grandfather, Joseph Jones. Please (a nod to Henny Youngman).
Joseph Jones was born in 1821 (probably in TN) and was (probably) living in Jackson County, TN when he married Elizabeth Sneed on 29 Dec. 1840. They moved to Crittenden County, KY before 1844 and to Montgomery County, IL in 1850. Elizabeth died there in 1886. Joseph remarried in 1887 and died in Montgomery County on 16 Dec 1898.
I did track down some other Joneses (imagine!) living in Montgomery County, IL at the same time he lived there and who seem to have followed a similar migration path of TN>KY>IL. But so did tens of thousands of others - many of them named Jones. I moved on to more promising areas of research.
However, when I was able to spend several days researching in Springfield, IL I included Joseph on my list of people to research. It was a fruitful trip though I found nothing helpful on Joseph until I noticed another late 19th c. marriage license included parents' names on the reverse side. I requested the film for his second marriage and crossed my fingers. I had a brief flash of excitement when I saw the spaces filled out - a very brief flash. There were his parents' names - John Jones and Patsy Smith.
Sigh. I am actually quite interested in Joseph. His daughter Cansada wrote to one of her granddaughters that her father's father was Haitian. Cansada, who outlived four husbands, had at least one husband who was listed as mulatto in Civil War records. Descriptions of her father and brother suggest they could have been mixed race. But I don't have the energy to track down a Jones - especially one who married a Smith. I leave that to younger, better minds than mine. Or until I have a good week in Jackson County, TN.