Paul did not like to boast or exercise his authority leading some in the Church of Corinth to believe that he had none. He had been patient with them, always seeking to teach and guide them: for building them up and not for destroying. To their own shame, they had sought to take advantage of what they perceived as weakness in Paul.
They had made the mistake of conflating Paul’s meekness and gentleness with weakness. These last few chapters then are Paul’s final warning to them: he is coming, and he is coming with authority.