It's part from my upbringing as:

来源: 于 2025-10-20 03:33:43 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

described in the preface I wrote for my Dad's autobiography.  See pic of it I took this morning:

(Note: my Chinese wirting then wasn't as good as when I was in high school)