A useful way to hold this word: something has been taken away, and what you are looking at is the shape of the gap it left. Not a thing that was never there — a thing that is gone. That is why bereft feels heavier than without: without reports an absence, bereft points at the removal. Turn the picture and you get a hall with no furniture or a team with no ideas left; turn it and you get a person with a hole where someone used to be.
Bereft is the old past participle of the verb bereave, to take something away from someone, written bireft in Middle English; it changes the way leave changes to left. A past participle names the state left behind after the action, which is exactly what the word does in both of its uses.
bereft 是動詞 bereave（奪走）的過去分詞，中古英語寫作 bireft，變化方式跟 leave 變成 left 一樣。過去分詞講的就是「動作做完之後留下的狀態」，這正好是這個字兩個意思在做的事。
Wiktionary entry supplied in this packet (kaikki:3f6f69a190036ae4:702170566 / :702172632): From Middle English bireft, v. Middle English bireven; synchronically a form of bereaved; compare leave and left.
Two branches
東西被拿走：完全沒有
缺口對著外面的世界：少掉的是希望、辦法、家具、生命這類「東西」。
adjective · C1
In the pattern bereft of something: completely without a thing that matters, such as hope, ideas, meaning or life. It often carries the feeling that the thing was once there, or ought to be there.
毫無…、完全沒有…
人被拿走：心裡空掉
同一個缺口轉向裡面：被拿走的不是東西，而是一個人，所以剩下的空位長在心上。
adjective · C1
Feeling very sad and very alone because someone you loved has died or has gone out of your life.
傷心又孤單