Here's the answer:
“很烧脑”
(hěn shāo-nǎo)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 93.03% of the time!
(hěn shāo-nǎo)
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 93.03% of the time!