This does not mean that Paul was proud and that God would have to deal with him by humbling him among them all. That idea does not fit the context at all.
It is possible not to repent properly, and then the sin has not gone away. It is still buried in us; it is ready to come out once again and redevelop. There was light repentance. Maybe there has been an outburst of proud anger. We say, ‘Lord, forgive me’, but we have not really repented of it. ‘I cannot live like this’, we say. ‘I do not want to inflict this upon my family and people around me.’ Well that is good. ‘I will desist. I will control myself.’ But it was not deeply enough repented of, so it comes back. But we can do that with all sorts of sins. ‘I regret saying that, I regret doing that, I regret that attitude. I regret failing in that duty.’ But have we wept it away? Has it been repented of? That is the cure. Not only for the cleansing of God but for the reorientation of our own hearts. You really reviewed your sin, not excusing yourself. You made sure you were really meant it before God and sought his forgiveness.