… and is there a story about it?
My middle name is Elizabeth, which was my grandmother’s name. I have 2 brothers and a sister; each of us got our middle name from a grandparent. Three of the four grandparents had names that started with “E”. My siblings & I have first names that start with the same letter, so three of us have the same initials. Three of the grandparents did not have middle names.
I’m happy with my middle name. My poor sister got stuck with “Elsie”.
I was born with the middle name of Ann, just because it sounded good.
Converted to Judaism and changed my middle name to Ruth.
Lynn
No story - just seems like every family born in the 60s has at least 1 lynn in the herd.
Arthur, son of Uther.
But seriously, it’s a nod to my paternal grandfather, which is sort of funny, since after he passed away about ten years ago we learned that his given name was Armando, but for some reason he was called Arturro. When he was a young man (in the early thirties) he changed his name to something more Anglo sounding, including our family name.
Mary, after both of my grandmothers – the Lithuanian grandmother was actually Mariana, and the WASP grandmother was always called Molly, but I’m named after both of them anyway 
“But”
Kerr.
It’s a tradition on my mom’s side of the family to give the oldest child the middle name of Kerr, so we have Clyde Kerr, Kate Kerr, Nan Kerr, and me, Lindsay Kerr.
Peter. My grandfather’s first name.
Ew.
“Olga”
I’ve been dying to find out whose ingenious idea it was to name me that. No one is 'fessing up.
Rae.
My father’s middle name is Ray. He’s named after his uncle Ray, whose daughter is named Rae Marie. All three of Rae Marie’s kids have the middle name Rae/Ray. One of their other cousins named their daughter Jessie Rae after me - although my name is Jessica Rae.
If I have kids, none of them will have the Rae/Ray name. The madness has gone on long enough.
Lee.
It’s my mother’s maiden name. Both my sister and I got Lee as middle name, and mom took it as a middle name after she married our dad, because she wasn’t given a middle name of her own!
Used to be Keith. When I changed my name in 1988, I ditched it.
McCoy
My Great-Great Grandfather stipulated that each first born male of his line had to incorporate on of his names in their name to receive their inheritance. He only had a daughter so the surname would not be passed on. Thus I, by tradition, have a choice of Frank, McCoy or Field for my as yet theoretical first born son.
For the longest time I though this was a legal requirement. I now understand it was his little narcissistic wish. The ‘inheritance’ is pretty damn crappy too. It is a cane with a solid gold top. My dissapointment in learning the true value of the object was crushing. I have yet to decide whether he will get his wish from beyond the grave should I sire a male child.
Michele. My father’s favorite song at the time was Michelle by the Beatles. I have no idea why I only got one “L” though.
Thomas.
Fathers first name.
Kathleen. No particular story behind it, as far as I know.
Kay - I guess it just scanned well with my full name.
Eylese - pronounced Elise
No idea where it came from. In 7th grade, I went by Eylese in the classes that the other Shannon was in, and by Shannon in the ones where I was the only one. By the end of the year I found out that most of my teachers though I was a set of twins but thought it really strange that we were never seen together.
My parents were so poor I didn’t get a middle name and my brother and sister have to share one.
When my oldest was born I borrowed my sibs middle name for him, then when my youngest appeared I gave him my maiden name for his first name.
Recycle!
Fiona. No special reason, except that my mother was born and raised in Scotland and likes the sound of it. My sister has another vaguely Scottish middle name… Shona. Quaintly enough, they rhyme. I like them both.