What are Mel Gibson's links, symbols and motifs?

when i ask this question i want to know if there is somwthing specific that gibson puts into his films such as the writer of the avengers series - he has been seen in every movoie of avenger as a symbol of his work. weather it is just that the main character of his flims represent a small part of his childhood or if a charachter wears an important iteam of his.