I really think it’s a strange coincidence that there could be two people named John Jacob Jingleheimer Schmidt. But it seems to work out okay for both of them.
You know, it never ceases to amaze me that every time I think of a witty response to a thread, someone has beaten me to it. :smack:
I think the only time it would be an issue is at the DMV (or maybe passports). I don’t have multiple middle names, but I am a “Jr”. When I got my license they insisted I fill the paperwork out and also sign my name using the JR since it appears on my birth certificate. They also rejected any proof of insurance papers that left off the Jr. So they might have some sort of similarly Draconian rules about middle names. Strangely, despite their insistence on ‘customers’ being precise, they seem to have no problem butchering names randomly when they print the license, turning random parts into initials and confusing hyphenated last names…
As a random aside, I worked with a fellow for whom all the male members of his family had the same last name, and each had the first name of just the initial “N” followed by a unique middle name. And I knew another fellow for whom all the male family members used their middle name as their identity rather than their first.
I have an uncle named C. William Lastname, but when he was in the Army, they insisted on switching it around to William C. Lastname (I still have his old stenciled duffel bag). Still, I suppose that’s better than the more technically correct Clement W. Lastname, since he always goes by Bill.
My father in law had no middle name, and many forms when he went into the military and civil service were filled in with “NMN” (no middle name). One or another of the agencies got it screwed up somewhere along the line and he ended up spending the better part of his career being “officially” John N. Lastname and having a heck of a time dealing with military and official agencies who insisted on knowing what that N. stood for.
Hilariously, he actually had one id card of some sort issued to John Nomiddlename Lastname, and an id checker actually asked how to pronounce that unusual middle name. 
All in all, having no middle name caused him no more trouble than having an unusually spelled name or too-long of a name would have. But it was funnier.
My brother has two middle names, and (other than a brief period of teenage rebellion), has always gone by the second of those. I have no idea what’s on his driver’s license and such, but I’ve seen some of his business paperwork, and it lists him as “Ra”. Apparently the state of Pennsylvania is cool with it.
I was blessed/cursed with two middle names, as well as a first name (Geoffrey) that until recent years, nobody ever pronounced or spelled correctly.
When I went into the army waaay back when, somebody gave me a tip to use only the initials. The army required a “payroll” signature on a bunch of papers, and had I given both names, I would have had to write out all four names every time I had to sign a form.
When computers first began to be used, often I’d try to give my name with the two middle initials, and they said the computer would only take one. I found an easy fix to that. I told them just to type in the first name blank, my name followed by the first middle initial, and to put the second one in the proper blank. Many were so happy to have somebody tell them how to beat the computer this way.
Here, at least, the DMV still cannot take two middle initials, so just use the first one. On my first passport, I used just one initial, and to this day it is still that way. Registering to vote, we are supposed to put in the full middle name/names and also on a home deed, but I still used just the two initials. Otherwise when I voted, would again have to write out both middle names.
What about you folks with multiple hyphenated names (John Smith-Jones Gaga-McGoogle)? How do you handle it all?
It didn’t seem to cause any problem to Francis Scott Key Fitzgerald, who usually went by his first initial and the first of his two middle names.
One thing I would not suggest is to have an entire name like A. Baker Dog. That is a first initial (or one letter name if you prefer). My nephew was “blessed” with this because his father Able Baker Dog didn’t like the name Able. It caused him endless problems with forms that insisted on first name middle initial.
My father also had no middle name, so the USMC issued him the letter ‘N’, for No Middlie Name.
On the other hand, I have a friend who is was given an extra middle name for a very specific reason. His parents named him something like Daniel Itzak Allen Cohen, putting the Goyishe name in next to last, so if it ever got anti-semitic he could quickly become ‘Dan Allen’. I thought that was a pretty interesting idea. So far it hasn’t been necessary.