I would like to know what "a satisfaction in the forbidden, a challenge" means in the following sentences:
I walked home slowly. The air was suffocating. The sky was grey, and sticky wind blew through the streets, swirling up dust. The few people around looked hurried, caught inside their own minds even more than usual, their faces like masks. I was relieved to get home. Pani Kolecka wasn’t there. I sat and took out the papers the professor had given me. My head was empty but I started anyway, placed pen to paper. I forced myself to think. I didn’t really want this, but neither did I want to let it slip away. I had nothing else, no other path. And there was a certain pleasure in doing what I had not allowed myself before, a satisfaction in the forbidden, a challenge. I knew what I really wanted to write about, the book that had moved me more than anything, more than any book before. But I also knew I couldn’t write about Giovanni’s Room. It had never been published in Poland. I wasn’t even supposed to know about it. But I had read Baldwin’s other stories. They dealt mostly with the Negro in American society, of his discrimination and shunning. I could see its relevance, could see how it exposed the double standards of the West, how it showed racism and white supremacy behind the liberalism and democracy extolled by the capitalist powers. At the same time, of course, I could identify. I carried my difference, my shame, on the inside. It wasn’t visible – not to everyone straight away, at least – but it was there, and it was a danger. That’s what I began to write about.
In this novel which is set in the 1980's in Poland under the socialist regime, where homosexuality was socially unacceptable, the protagonist Ludwik (a university graduate) left Poland in 1981 to live in the United States of America. And he remembers what it was like back then in Poland, where he, now finished his studies at college and searching for his career, visited his literature professor's office and told him that he decided to apply for a doctorate after all. (He had declined his professor's proposal about the doctorate, thinking that the professor would force him to write about a topic foolish yet politically useful.) At this, his professor told him to write a proposal to be submitted to the board and bring it until the weekend so they can review it together. So he returned home and began writing his proposal.
In this part, I wonder what "a satisfaction in the forbidden," and "a challenge" mean. Does the former perhaps mean that he was satisfactory/fulfilled by doing what was forbidden? And, does the latter perhaps mean that he felt a drive/will/propulsion in doing so...? Or that he found writing the proposal challenging...?
I am an English learner from South Korea, so thank you for your patience in advance as I may not know obvious things. I would very much appreciate your help. :)