Where did the apostle Paul study?

A:Acts 22:3 says that Paul was brought up in Jerusalem and educated by Gamaliel I, who flourished in Jerusalem around 20-50. On the other hand, Raymond E. Brown (An Introduction to the New Testament) says that this claim probably needs qualification because Paul's letters do not suggest that Paul had seen Jesus during the public ministry or at the crucifixion, and so implicitly cast doubt on Paul's continuous presence in Jerusalem in the years 26-30/33. Others contend that Paul does not show evidence of technical rabbinic training in his letters.