Explain clearly what, according to Salarino, would make a person sad in Antonio's position.

In act 1, scene 1, Salarino discusses Antonio's melancholy mood and believes that he can explain why Antonio is upset. Salarino believes that Antonio is worried about his merchant ships that are out at sea. Salarino tells Antonio that he has every right to worry about his ships traveling on the dangerous, unpredictable waters and mentions the numerous trivial things that would remind him that his ships are in danger on an everyday basis. Salarino sympathizes with Antonio's difficult situation and genuinely believes that Antonio is concerned about his valuable ships sinking, which would result in his bankruptcy. However, Antonio mentions that the well-being of his merchant ships does not concern him because his financial situation is quite healthy. After Antonio tells Solanio that he is not heartbroken either, Salarino suggests that Antonio is sad simply because he chooses not to be happy.