as mad as a march hare字面意思疯狂得像三月的野兔一般，引申为疯狂地；疯疯癫癫

【例句】
We had an argument yesterday and he smashed all the plates in the kitchen – he was as mad as a March hare!
昨天我们吵了一架，他把厨房里的盘子都摔碎了，他当时真是发疯了！

When I started dancing, they all looked at me as if I was as mad as a March hare.
我一开始跳舞的时候，他们都看着我，就好像我在做一件很疯狂的事。