Short Answer: Because it was rated "Arrrr!"
Explanation: The boy couldn’t go to the pirate movie because it was rated "Arrrr!" This is a play on words, as "Arrrr!" sounds like the pirate exclamation "Arr!" and also resembles the word "R" which stands for Restricted. The use of the pirate theme adds a humorous touch to the answer. 🏴☠️🍿