I go by the shortened English version of my Spanish first name. Let’s say my name is Guillermo (not my actual name), I go by Bill.
Is this a new tradition? In the New Testament, it was expected that John the Baptist would be named Zechariah, after his father, until Zechariah insisted that his name be “John”.
(and yes, “in the past two thousand years” does count as a “new tradition”, in the context of Judaism)
I legally changed my name when I was 19, deleting my first name (unused by me since middle school, converted to an initial when applying for college), making my middle name first, adding my writing pseudonym as two middle names, and retaining my surname. I’m happy with it, but different entities have chosen to use middle-1 or middle-2 for unknown reasons.
I just did a 30 second check and Chabad, for what it’s worth, says that it’s specifically an Ashkenazi tradition.
Both my first name and middle name are fairly uncommon, and I have no idea where my folks came up with them. My 3 older siblings have names from the Bible. I never really liked either of my names (probably because they were somewhat unique), so I have gone by my initials ever since high school.
I said I was called a nickname of my middle name.
Actually I have no real middle name.
My front name, and middle name are hyphenated. Think Mary-Ann. But it’s so seriously worse. 17 characters with the hyphen. And, my surname was very long as well.
Let me tell you, it has been the biggest PITA ever. Fits on no form. Ever.
I don’t have one, just firstname surname.
I joke that my middle name is “danger” when asked 
Anyway my friends call me “Frodo” in real life too (It was my username in the BBS were I met some of them, it extended to the rest of them )
Frodo Danger Baggins. Name checks out. 
International hobbit of mistery…
If anyone’s kneecaps need assassinatin’ he’s your man hobbit.
I use my first name, but people I went to school with and people who don’t really know me often use the most common nickname for that name.
This is totally unscientific.
While doing genealogy research of my family it struck me how many in the past went their middle names. This was on multiple branches and on both the paternal and maternal sides. This convinced me that it was much more common from the Great Depression back into the 19th century. That, along with very loose spelling standards, made research much tougher.
I have always disliked my first name.
My maiden name was mispronounced so when I married way back when, I got a wonderful last name.
When I meet people now, I tell them to call me by my last name, which some people actually have for a first name.
First name at work or with older family; otherwise I go by Kron.
I’ve always gone by my first name, although when I was a kid my mom sometimes called me by my middle name. Not as a warning, but more as a term of endearment. I like my first name. I’ve never had a nickname, and my name does not lend itself to nicknames.
I’ve known quite a lot of people who go by their middle names. Two of my closer friends who did had different reasons: one because she hated her first name; the other because he was named for a grandfather but everyone knew he’d be called by the middle name.
My middle name is an old family surname, which sounds more like a town in central Europe than a human name so that was right out. Unfortunately, my grandfather, father, and I all had the same first name, so I went through most of my youth being referred to as “Young Kent” by my family.
Nope, nobody ever came up with nickname like Skippy or Red for me, either.
This is mainly why my brother was known by his middle name. My mother’s family was Sephardic, she wanted him to have a first name same as a living relative in my father’s Ashkenazi family. The rest is like a 1950s sitcom plot.
So Lobelianne-Adelaide, how you doin’?
Ain’t it purty?
Addy to you, sir.
Always gone by my middle name. First name is Robert (and no, I wasn’t named after Bobby Darin).
I say always, but I once worked somewhere where my supervisor was a (very nice) woman from Honduras who couldn’t pronounce “Darren” and used my first name–which she pronounced “Lobear”.