Jean-Paul Charles Aymard Sartre:
( 21 June 1905 – 15 April 1980 )
French philosopher, playwright, novelist, screenwriter, political activist, biographer, and literary critic, considered a leading figure in 20th-century French philosophy and Marxism. Sartre was one of the key figures in the philosophy of existentialism (and phenomenology).

To read a poem in January is as lovely as to go for a walk in June.

Possession is a friendship between man and things.

To read a poem in January is as lovely as to go for a walk in June.

What the theater can show most movingly is a character in the making, the moment of choice, of the free decision which engages a whole morality and a whole life.

Every word has consequences, every silence too.

I exist. It is soft, so soft, so slow. And light: it seems as though it suspends in the air. It moves.

It is in anguish that man becomes conscious of his freedom.

Man is not sum of what he has already, but rather the sum of what he does not yet have, of what he could have.

I’m always conscious of myself—in my mind. Painfully conscious.

Jean-Paul Sartre, La Transcendance de l’Ego (1936/37), Jean-Paul Sartre, L’Être et le Néant (1943) — English: Being and Nothingness, Sartre elaborates there that consciousness is always already “co-conscious of itself”, without the need to hypostatize a separate Ego in experience. Relevant (real) Sartre formulations 📝: “Toute conscience positionnelle de quelque chose est en même temps conscience non positionnelle (ou non‑thétique) de soi.” Free English rendering: “Every positional act of consciousness of something is at the same time a non‑positional (non‑thematic) consciousness of itself.” Source: La Transcendance de l’Ego (and resumed in L’Être et le Néant). In Being and Nothingness, Sartre develops this further as “pre-reflexive self-consciousness”: Consciousness is aware of itself in and through its orientation toward the object. Work: Being and Nothingness (L’Être et le Néant). The Transcendence of the Ego (English translation often: The Transcendence of the Ego). (English: Nausea). The thought in question can be found mainly in The Transcendence of the Ego and Being and Nothingness. Example for clarification 👀: You are reading a book with concentration: You are not explicitly concerned with yourself, but there is implicit self-consciousness “I am the one reading.” When someone calls your name, your consciousness can shift to reflection (“am I distracted?”). The former is pre-reflective; the latter reflective. Conclusion 🧭: The quote in question is not an authentic literal Sartre quote, but an accurate paraphrase of his teaching on pre-reflective self-consciousness.
There is no such thing as a given freedom; you have to conquer your passions, your race, your class, your nation, and conquer other men along with you.

Once freedom has exploded in a man’s soul, the gods can do nothing more against him.

Duty is the will of the other within me, the alienation of my own freedom.

Three o’clock is always too late or too early for anything you want to do.

Freedom is what you do with what’s been done to you.

With despair, true optimism begins: the optimism of the man who expects nothing, who knows he has no rights and nothing coming to him, who rejoices in counting on himself alone and in acting alone for the good of all.

What he means by the statement (or the paraphrase thereof) is typical of Sartre: despair (in the sense of no hope for external salvation) is not passive, but rather the beginning of a radical optimism rooted in personal responsibility and action for a broader human interest.