茅塞顿开

máo sè dùn kāi

to suddenly see the light

Character by character

茅máo
thatch

塞sè
blocked

顿dùn
suddenly

开kāi
open

听了您的解释，我茅塞顿开。

After your explanation, it all suddenly makes sense.

Tone: positive (praise).

塞 is sè here. A way to thank someone for an insight.

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