Consider who you are. If you remove external objects, structures, circumstances, who are you in essence? What makes you, you?
Are you your personality, or do aspects of your personality change? Are you your body? What external forces impact upon your personality or body that have no power to change who you are?
Have your experiences changed who you are? Will other experiences change who you are? If aspects of you are changeable, then they are not core to your being. So what is?
Can you be whittled down into one truth about yourself? If you believe in the soul, is your soul unchangeable?
If you don’t believe in a soul, then isn’t every single aspect of you changeable and entirely dependent on the world around you?
Is your gender a core essence of who you are?