They thought they knew

[dukealien]

An unfortunate man, they said,
As they all rushed to watch him drown.
Yet for nothing else would he trade
His death. He's happy as a clown!
By Jove, they are so foolish!
As he isn't man but fish.

Behind the black mirror,
The truth hides with candour.

But it must be said, they always thought there was something a little fishy about that guy...