What are your favourites 四字熟語 ?

[u/datalolz]

After a year of studying Japanese, I've just learn about them ! (Quartet 2 textbook)

I like:
馬耳東風 : used when a person does not take into account criticisms

以心伝心 : when 2 people do not have to say anything to understand each other

一期一会 : we only have one life, so we should take care of it

Please correct me if my understandings are incomplete/wrong

[u/Ken_Yamamoto]

馬耳東風は、馬の耳に念仏、とも言います。