Answer: Because his childhood dream was to become a steamboat driver.
Step-by-step explanation:
His youthful ambitions were directed in that direction. He had always wanted to become a steamboat driver. It's where he grew up and is very sentimental. He points out that it is a call that brings a lot of adventure with him, and an interesting detail when he says that in such a situation, he would never have to pay for the ticket.