I honestly don't know what "gender identity" is. Any "feelings" of being female I have ever had come from my biology, starting at puberty: falling in love with boys, realising they wanted my body, being harassed by boys whose advances I rejected, menstruation, abortion, pregnancy, childbirth, mothering, menopause.
Post menopause, there have been no female-specific experiences for me. I am lucky to be in robust health, touch wood.
Apart from these female-specific experiences, I do not feel I am female. I don't constantly think "I am a woman" when going for a walk in the woods, reading a book, watching a film, going on a holiday, relaxing in the garden, taking a shower, etc. I would be hard pressed to describe what it feels like "to be a woman" as a thing apart from those experiences linked to my specific anatomy. I'm just me. Yet men thing they know? 
I am not cis and don't need this word to describe myself.
Gender identity is just a mental concept. It's in the head; buzzing thoughts. It does not actually exist, yet laws are being changed and society is being remodelled on the premise that it's a thing. Words are being invented, women are being erased, crimes are being committed, all given government's nod.
The mind boggles. It's truly scary.