grammar - Why use あんなに instead of こんなに when expressing one's memories?

My textbook contains the following dialog where 鈴木さん interviews her 課長 about what he did last evening:

鈴木「焼き鳥屋ですか。その店、いかがでしたか。」
課長「安くて、おいしかったよ。あんなにおいしい焼き鳥を食べたのは初めてだなあ。」
鈴木「そんなにおいしかったんですか。」

My previous understanding of こそあど was that

• こ refers to something closer to the speaker than the listener,


• そ refers to something closer to the listener than the speaker, and


• あ refers to something equally distant to both the speaker and the listener.

From this, I would think that the tastiness of the 焼き鳥 is much closer to the 部長 (he was there and had them, 鈴木さん was not), and, therefore that he would use こんなにおいしい, but my textbook says (but doesn't explain why) to use あんなに when talking about one's memories of a past experience.

To put it differently, I thought that あんなにおいしい would be appropriate if both 鈴木さん and her 部長 had been at the 焼き鳥屋 together. I interpret 鈴木さん's response, そんなにおいしかった, in the same way, that the experience is closer to the 部長 because she wasn't there.

Could someone explain the point I'm missing? Thank you.

Answer

Like you say こ～ means close to the speaker, so

こんなにおいしい。

would be appropriate, when he is actually eating the food, e.g.

こんなにおいしいとは思わなかった。
I never thought it'd be this good.

---

そ～ means close to the listener.

そんなにおいしかったの？
It was that good?

---

あ～ means far from both the listener and the speaker (in my opinion not necessarily equidistant).

あんなにおいしい焼き鳥を食べたのは初めてだった。
First time I had 焼き鳥 that good.

At the time of speaking the tasty 焼き鳥 is far from both the speaker and the listener. Here far doesn't necessarily mean far in terms of distance, but could be far in time. Then memories are always far from both listener and speaker and あんなに is usually appropriate.

In English, too, using "this" for memories does not work.