I am looking for a word, idiom or a phrase to describe an attitude when someone is able to and often publicly makes fun of one's own deficiencies.
Having an objective, critical, maybe even cynical view of one's own capabilities or actions and having enough confidence in one's abilities so that one is not worried about bringing them in public.
A regular modesty (謙虚), effacing (目立たない), self-effacing (控えめな) do not convey the meaning of self-confidence. At the same time they suggest a reserved attitude, while I am looking to describe someone who purposefully makes fun of his own mistakes.
Update: I am looking for a phrase that captures the essence of self-deprecating as explained here:
A self-deprecating person knows her own weaknesses and shortcomings and isn't afraid to point them out, often in a humorous way. (...) Being self-deprecating is usually considered a good trait, a quality of someone with a wry sense of humor.