What exactly does the grammatical form NがNなだけに mean?

Question

In my JLPT textbook, it has a section explaining the verb form [Noun]が[Noun]なだけに. By way of explanation, it says that this means, "unlike other things, [Noun] is special, so..."

I'm having a hard time reconciling this explanation with the examples given.

Here is one example provided:

A : 部長{ぶちょう}に連絡{れんらく}しなきゃいけないんだけど、時間{じかん}が時間{じかん}なだけに電話{でんわ}はまずいよね。

B : そうね。とりあえずメールだけ送{おく}っておいて、明日{あした}の朝{あさ}報告{ほうこく}したら？

So... on A's sentence, we need to contact the department head, but "unlike other things", time is "special", and so it would bad to call? It's just kind of nonsensical to me. B's sentence only confuses me more, because apparently we can email tomorrow and that's fine... so it's bad to call now because it's too soon, and better to wait and send an email? To soon how?

Another example given:

状況{じょうきょう}が状況{じょうきょう}なだけに、家族{かぞく}の許可{きょか}をとっている暇{ひま}がない。とにかく手術{しゅじゅつ}を始{はじ}めよう。

In this situation I at least understand what's going on. We don't have time to wait for permission from the family, we should start operating. Okay, but why? Because the circumstances are "unlike other things"? What other things are we comparing to? Other options for trying to help the patient? Other circumstances the patient might have been in?

Intuitively, to me it seems like in this case the way to think of 状況{じょうきょう}が状況{じょうきょう}なだけに is that it conveys an idea similar to, "the circumstances are what they are." In other words, we've got what we've got, so there are no other ways of dealing with it. But that's just my feeling and I've let my intuitions on Japanese grammar mislead me before.

What exactly does [Noun]が[Noun]なだけに mean?

Answer 1

This may be a weird thing to say but if one already knew what 「[Noun]が[Noun]なだけに」 meant, that explanation in your book would make pretty good sense with minor alterations.

"unlike other things, [Noun] is special, so..."

↓

"unlike other [Noun]s, this particular [Noun] is so special that..."　

「[Noun]が[Noun]なだけに」 describes a special kind of situation requiring an equally special kind of action or treatment.

From the sentence:

「部長に連絡しなきゃいけないんだけど、時間が時間だけに電話はまずいよね。」

One would know that an unexpected event occured very late at night, so it would not be a good idea to call the boss immediately. It does not say "too soon" as you stated. It is saying "too late at night". How do I know? I know from the last part of B's reply --- 「明日の朝報告したら？」 = "Why don't we report to him tomorrow morning?".

To repeat, it is saying:

"unlike other times (of the day) this time (of the day) is special, so ~~"

It is NOT saying:

"unlike other things, this time (of the day) is special, so ~~"

Answer 2

Since nobody has touched upon this:

[Noun]が[Noun]なだけに

is just one manifestation of a more abstract pattern, which is "[Noun] [(same) Noun] copula".

時間も時間だし、帰るか It's getting late, let's go home
性格が性格なので、友達があまりいない He doesn't have a lot of friends because of his personality

The rough meaning is that the [Noun] is unusual/extreme, or calls for (special) action in some way. Like in the second example above, it can sometimes be useful when you want to be purposely vague about how [Noun] is unusual/extreme.

"[Noun]が[Noun]なだけに" is just this pattern with だけに and its usual meaning.