Coy Mathis is six years old, and she just wants to use the bathroom at school. For a year and a half, it wasn't an issue. But in December, Coy's school informed her parents that she would no longer be permitted to use the girls' restroom. She would have to use the boys' room, the staff bathroom or the one in the nurse's office. Why? Because Coy was assigned male at birth.

Coy is one of many transgender and gender-nonconforming children in the United States who face discrimination, harassment and bullying – from adults and kids alike – simply for existing. Coy's school didn't report any problems with her using the girls' room; they barred her from it nonetheless, singling her out for a special bathroom. According to a letter from the school's lawyer, published by the New York Times:

"As Coy grows older and his male genitals develop along with the rest of his body, at least some parents and students are likely to become uncomfortable with his continued use of the girls' restroom."

Putting aside the creepiness of the school's concern for one of its student's genitals, and that in 29 years of using women's bathrooms, I have never once caught a glimpse of anyone else's bare crotch, it's worth asking: why should the potential future discomfort of yet-to-be-discomfited students or parents trump the right of a six-year-old kid to be treated like everyone else?

Discrimination against transgender people is real, pervasive and often legal. And it often builds from ignorance and bias – things that start young.

"What we generally see is that most people support transgender rights," Michael D Silverman, executive director of the Transgender Legal Defense Fund, told me. He continued:

"Most people don't think that a person should be fired from a job because they're transgender, or thrown out of their home because they're transgender, or discriminated against at school because they're transgender. "When we do see resistance, it's often something that can be resolved through education and discussion. One of the things we see in transgender rights advocacy is that people just don't know a lot about transgender people and what it means to be transgender. One of our most effective advocacy tools is education."

He's right. While transgender people do face widespread mistreatment, the discrimination doesn't make much sense. Who, exactly, gets hurt if folks match their physical appearance to their gender identity? Why is it such a problem for a six-year-old girl to use the girls' bathroom?

Everyone has a gender identity. You do, and so do I. Just as the gay rights movement has made us collectively realize that we all have a sexual orientation – whether it be straight, gay, lesbian, bisexual or something else – advocates for transgender rights try to impart the lesson that each person has an internal sense of being male or female (or, for some folks, neither, or something in between). As Silverman says:

"We all have a gender identity. We just never have to think about if it we're not transgender because no one questions it."

For many of us, that internal sense of maleness or femaleness matches up with the doctor's message when we were swaddled in a blue blanket or a pink one. For transgender people, it doesn't. It shouldn't be that big of a deal: Mary's gender identity lines up with her gender assigned at birth, and Suzie's doesn't. Mary is Mary, Suzie is Suzie.

Many of us take steps to match our gender identity with our physical appearance, even if we aren't fully conscious of it – I identify as a woman, and I wear my hair long, pluck my eyebrows, shave my legs and sometimes wear skirts. Many transgender people do the same thing, and seek to match up who they are on the inside with the social, cultural and physical markers on the outside – by wearing clothes typical of their gender, taking hormones, changing their names or having surgery.

They're met with continual resistance. While states make it relatively easy for women to change their names when they get married, changing your name to match your gender can be a laborious process. It often requires getting a court order from a sympathetic judge, signed and notarized affidavits from friends or family members and, in some states, paying for a newspaper ad to announce your new identity.

The path to physical transition can be rife with roadblocks. For transgender people who want to undergo medical treatment, being withheld transition-related healthcare is just as devastating as being withheld any other form of medical care. But most insurance companies have healthcare exclusions that block payment for transition-related care, and most state Medicaid programs don't pay for gender transition, either.

That means transgender people are often stuck paying for their most basic healthcare out of pocket, to the tune of tens of thousands of dollars. The many transgender people who can't afford care are left without it; some turn to below-the-radar, freelance "doctors" with little to no medical training. Procedures are routinely botched, disfiguring, maiming or even killing people.

By contrast, if a person whose gender identity matches their physical characteristics at birth ("cisgender"), but then a hormonal imbalance changes their physical appearance contrary to that – if a woman grows significant amounts of dark facial hair, or if a man develops breasts – health insurance typically covers treatment.

Transgender people can also be fired from their jobs, denied housing and generally discriminated against with no legal recourse in many US states. Of the LGBT hate-murders committed in 2010, transgender people accounted for 44% of victims, with trans people of color disproportionately targeted. Transgender youth face high rates of bullying, homelessness, abuse and physical and sexual assault.

I realize this all sounds quite dire. While transgender people do face tremendous challenges from discrimination and bigotry, most transgender people live just like everyone else: normal, happy lives, doing the best they can and surrounded by loved ones.

Yet, the obstacles transgender people face are almost entirely social constructs: we've made a collective societal choice to deny them freedom from discrimination, access to medical care and equal treatment under the law. We can choose differently. We can choose to treat our fellow human beings as human beings, and not as unnatural threats to a gendered order of society or as cruel punchlines.

The best place to start is in schools. Silverman sees this, too:

"As we think about education around transgender issues at school, it's important to remember how much relates to the core mission of schools. "In Coy's case, for instance, her school has the opportunity to teach students a powerful lesson about respect, fair play, tolerance and treating others with kindness. That's a lesson that all schoolchildren would benefit to learn."

We can let a little girl use the bathroom, I think.