I have a theory. Basically, society has assigned "gender" to certain traits or feelings, such as girls liking cute things, or boys being more aggressive, so when people say they feel like a particular gender, what they're actually saying is that they identify with traits or feelings that society has assigned to that particular gender; thus, if a biological male likes cute things and loves dresses, they might say that they identify as female. This would, however, be regressive in terms of social development, since for the past few decades, even going beyond the first wave of feminism, we have been trying to remove the idea of gender roles, so it would be saying that it is perfectly fine if a girl is as aggressive as would be expected of a boy, or if a boy loves cute things without having to identify as a girl. Essentially, this would be an affirmation of traditional gender roles, if that makes sense.
@Randomizer
I'm wondering what Mogu is wanting to escape from, whether it is social expectations, their personal understanding or misunderstanding of what it means to be a boy, etc.