From N.T Wright’s Paul: A Biography:
We easily forget that the author of these letters spent most of his waking hours with his sleeves rolled up, doing hard physical work in a hot climate, and that perhaps two-thirds of the conversations he had with people about Jesus and the gospel were conducted not in a place of worship or study, not even in a private home, but in a small, cramped worship. Saul had his feet on the ground, and his hands were hardened with labor. But his head still buzzed with scripture and the news about Jesus. His heart was still zealous, loyal to the One God.