Self-criticism is the act, or the habit, of judging your own behaviour and character — especially when you believe you have done badly. It is the noun that sits next to self-critical. A short, honest look at a mistake can help; a long attack on yourself is something else, and English still uses the same word for both, which is messy but true. You will hear it in essays, in talk about the mind, and in serious conversation about growing up. Though actually, the word also has a political life: in some parties and states, “self-criticism” meant standing up in a meeting and listing your faults in public. That use is heavy and official, not the quiet “I should have been kinder” of everyday life. In ordinary English it is not a joke and not a swear; it just names the looking-inward. It is not criticising someone else, and it is not a review of a book or a film unless you are talking about yourself as the maker.