When I was an undergrad Psychology Major at Michigan State University, I was briefly a Teaching Assistant in a course called Human Sexuality 101. I lived in two different dormitories before switching to apartment living. I did not meet a single trans person in 4 years. The issue was never discussed in class.
I spent nearly 5 years as a caseworker. One year taking Medicaid applications. Two years Basic Family Services and two years Employment and Training counseling. I met one trans person. They were seeking financial help for proposed surgery.
In the next 32 years, I worked at several major health insurance companies. I met thousands of employees at Open Enrollment and Health Fairs. Worked on unique claim problems, appeals, and plan design. Not a single issue, question or disputed coverage related to trans. Not one.
Things have obviously changed. Can it truly be nature or is it nurture?