Dan was afraid because he never encountered a shark before.
What made him afraid of sharks?
He did a lot of drawings about sharks after seeing a shark documentary.
It's okay to be afraid of sharks especially after watching documentaries. Sharks are often displayed as dangerous and threatening.
It's not that bad, don't take this so serious.
There's nothing wrong with your friend being afraid. Sharks can be scary. Maybe you can help him overcome his fears instead of drawing attention to it?