Jeanne Calment in 1996, on her 121st birthday. She still had a year and a half to go. Image source
The oldest person ever to live (as far as we know) was Jeanne Louise Calment. She was born in 1875 in Arles, France, and died in 1997, in the same city, at the age of 122 and a half.
She met Vincent van Gogh when she was thirteen, and says he was “dirty, badly dressed, and disagreeable,” as well as “very ugly, ungracious, impolite, sick.”
Calment at age 20, circa 1895. Image source
She saw the construction of the Eiffel Tower…and the launch of eBay. She was alive during the administrations of Ulysses S. Grant…and Bill Clinton. Had her husband lived as long as she did, they would’ve been married for 101 years.
I don’t have anything profound to say. I just think that’s amazing.
Brian D. Buckley 
My mother made it to 98, and if somebody had offered her another 24 years, she’d have declined (and possibly smacked them in the face). She was cogent pretty much up until the end, but there were fewer and fewer things she could do, and she didn’t see much point in just sitting around. But to make it to 122 and still be at least somewhat functional, that’s amazing.
Oh, and my mother was an art historian, so she’d have liked the van Gogh story. I gather from things that she said that many great painters were not really people you’d want to hang out with.
98, that’s impressive! But yeah, quality of life is certainly a big factor.