“drink like a fish”不是指“像鱼一样喝”，真实含义是豪饮，饮酒过度，酗酒，如牛饮水。

【例句】
I'm not surprised to hear that Karl got drunk again last night —that guy always drinks like a fish!
我并不惊讶Karl昨晚喝醉了，那个家伙总是饮酒过度。

When I was young I could drink like a fish and eat like a pig.
我年轻时酒量和食量都很惊人。