The Hats
The hats themselves are a reference to enduring life’s tests. Bartholomew wakes up one morning with the hats stuck to his head, and as a result, faced much animosity and cruelty by the people of the kingdom. However, in the end, it is the hats that free him and make him money.
The Wise Men
The Wise Men are perhaps a reference to older adults. One would expect them to be wise due to their life experience – yet, even they are unsuccessful in getting the hats off Bartholomew!
The Executioner
The Executioner himself is a symbol for the complex nature of humans. One would expect him to be cruel and unforgiving, due to the nature of his job, but instead he is considered a “pleasant man” who refuses to cut off Bartholomew’s head. This suggest that not everyone behaves the way they are perceived at first glance.
“Hats off to the King”
When the Captain of the King’s Own Guard tells Bartholomew to, “Hats off to the King,” he is physically unable to do so. Perhaps this is Seuss' way of emphasizing the fact that many in the Kingdom are unhappy with the King's reign.