Then there is also a significant risk of becoming the type of Mary Sue that is disliked, a character who can solve any problem quickly and easily, one who never struggles and usually never grows.
Simply because, it’s hard to make a self-insert that feels real because to do so requires you to face yourself, acknowledge your flaws, and put all of it, good and bad, out in the open. That’s why most riders avoid it, a self-insert is the hardest thing to do right.
