One way to hold this word: the careful look a doctor or an inspector gives something, turned around and pointed at yourself. The looking is slow, it follows a method, and it is done to find what is really there rather than what you hope is there. What changes between the two meanings is only what you are looking at — your own conduct, or your own body.
這個字的畫面可以想成：醫生或檢查員仔細端詳一樣東西時的那種目光，被轉了個方向，對準自己。這種看是慢的、有方法的，目的是找出實際存在的東西，而不是你希望存在的東西。兩個意思之間換的只有一件事：被看的是自己的行為，還是自己的身體。
From the word’s history
Wiktionary analyses the word as self- + examination, with self- traced back through Middle English to Old English self.
根據 Wiktionary，這個字就是 self- 加上 examination；self- 這個前綴經由中古英語一路上溯到古英語的 self。examination 本來講的是把一樣東西仔細看過一遍，前面掛上 self- 之後，被看的對象就變成自己。
Wiktionary, "self-examination"
登入就可以看每一支怎麼連回核心畫面。