不假思索
bù jiǎ sī suǒ · HSK 7
to act without taking time to think
⚡ bù jiǎ sī suǒ = not borrow thinking searching — no need to think first
Each piece: 不 (not) 假 (borrow/rely on) 思 (thinking) 索 (searching). You skip the whole search-for-an-answer step — the response just fires instantly, like a reflex.
不 — single pictograph; bird flying upward
Originally a pictograph in oracle bone script, traditionally interpreted as a bird flying up toward the sky and unable to come down, suggesting negation or refusal. Over time it became the standard negation word in Chinese, used before verbs and adjectives to mean 'not'.
假 — person radical 亻 + 叚 (borrow)
假 combines the person radical 亻 with 叚, which originally meant 'to borrow' and provides the sound. The core idea is a person borrowing something, which extended to 'borrowed,' 'not real,' or 'fake.' From there it also developed the meaning 'leave/vacation' (time borrowed away from work).