How would you say “for all I know” using 限り/限る in Japanese?

Question

The best I can think of is 僕が知る限り + fact + とは限らない. Does this work, are there better alternatives?

Answer 1

If I understand you correctly, the phrase you're looking for is more about entertaining extreme/absurd possibilities, or humorously saying how little you know about the matter, rather than a sincere “to the extent of my knowledge”.

Variations on “知る限り” will work when you are being sincere, but it doesn't really work in a sarcastic way. I'd say it's closer to a “to my knowledge” or an “as far as I know”:

僕の知る限りではいい人だよ
As far as I know, he's a good person.

When you're just putting out some extreme possibilities, you might consider variations on “可能性もある”. Literally, it means “there is even the possibility that…”, but I think the sentiment can be close:

• 35年という期間は長すぎて、働けなくなる可能性や、それこそ死んでしまう可能性もあります
  35 years is such a long time, you could become unable to work, or for all you know you could be dead.
• あの人はあまりにもよくテレビに出ていて、毎回 別人の可能性すらある
  He's on TV so frequently, for all I know it could be a different person each time.
• プロフィールは全くのデタラメの可能性もあるのです。相手が故意にウソをいってだまし、犯罪に巻き込もうとしている可能性さえ考えられます
  Profiles can be completely fake. For all you know, the person may be lying to deceive you, trying to involve you in a crime.

_{(Examples taken and edited from the internet.)}

Answer 2

I think what you have is fine, but I would say it as 私の知っている限り.

Answer 3

My suggestion is "僕【ぼく】の理解限界【りかいげんかい】[と言【い】えば・について・に関【かん】して]...."