no, self-ID is stupid, you can't "choose" but being trans is a real thing

when you see a woman out on the street, you know she's a woman based on how she looks, speaks, acts, not by checking her genitals or chromosomes. gender is both a role you play, and a way you feel about yourself

for a small percentage of people, the gender they experience doesn't line up with their biological sex, and this causes them distress. and to alleviate that distress, some people transition: change their name, pronouns, clothes, voice, hormones, etc.