What does 2 Corinthians 12:13 mean?

Paul sounds frustrated with the Corinthians. They know him. He lived among them, founding the church in Corinth and leading many to faith in Christ. God even performed supernatural signs and wonders through Paul right in front of them. Why did they not defend him to the false apostles who came to them later and talked Paul down?

He now asks if this has something to do with the Corinthians comparing themselves to other churches Paul planted. He asks how they were less favored than any of the others. In other words, did they think they were treated badly by Paul in some way?

He answers his own question by suggesting one way they were treated differently: He did not burden them financially. That is, Paul refused to take any financial support from them to meet his own needs. He adds sarcastically, "Forgive me this wrong!"

This issue of Paul refusing personal support from the Corinthians has been a point of contention between them for some time. He wrote about it in the previous letter known as 1 Corinthians (1 Corinthians 9:11–12) and earlier in this one (2 Corinthians 11:7–12). Despite protests that the believers in Corinth want to pay for Paul's services, he refuses. This is in order to be beyond reproach about his motives for serving them on behalf of Christ.