How to file FBAR if you do not have all necessary bank accounts information?

The BSA E-filing (http://bsaefiling.fincen.treas.gov/NoRegFBARFiler.html) does include detailed instructions on how to fill up the FBAR form - which is great if you actually remember all of your bank accounts (including the ones that your Mom or Dad or Granny opened for you when you're a 4-year-old kid), how much you have in those bank accounts, and that the banks didn't turn your bank accounts into "dormant" accounts due to lack of activity while you're in the U.S.

Too bad that there are no guidelines out there on how to file FBAR when you don't have all the information you need, and since I can't afford to hire a tax attorney, I will just have try my best to figure it out on my own...and if IRS feels entitled to penalize innocent foreign account holders/expats/new residents, I (we) will call for John Oliver's help to make fun of them on tv!
(if you can afford to get professional advice, please do so. But tax professionals aren't necessary reliable, so please choose yours wisely. I hired H&R Block to do my 2011 tax return and they didn't tell me about FBAR and 8938)

My initial "delinquent FBAR" filing is far from exemplary, but I am sure there are many of you expats out there (who traveled from somewhere really far to work in the U.S. and didn't think of bringing along your bank books) might find my story to be useful...especially if you are, like me, unable to access old bank account information.

So, why did I file my FBARs when I don't have all of my overseas bank account information?
Well, I was already late (which is, bad enough) but I suppose that is one way we can tell the Treasury or IRS, "Yo, we're not some rich people trying to evade tax or hide money or whatever it is that you assume. We just don't have access to the information, and we'll give you the information that you request as soon as we have them. (and if you, IRS or Treasury employee have any common sense, you will at least understand that if you're a U.S. citizen who happens to be working in ...say, China or Russia and you suddenly find it mandatory for you to report all of your bank accounts in the U.S. to a Chinese government equivalent of the FBAR and Form8938, you will feel just as helpless as I (we) do right now)"

Here's what I wrote for the 'filing name' of the FBAR form:-

Reason for filing late, I chose "others", mentioned that I "did not know I had to file" and also mentioned that this FBAR filing thing is "not the norm" in other parts of the world (not my exact words, but I feel they have to know how ridiculous and unreasonable this FBAR thing is. They can't just do things differently compared to other governments in the world and then expect new residents in the U.S. to be automatically aware of them).
Of course, other websites advised that it's  better to just choose "did not know I had to file"