Few people in America face more discrimination and are more misunderstood than transgender people. Often, it is the misunderstanding that leads to the discrimination. Tonight, the "CBS Evening News" with Scott Pelley will try to shed some much-needed light on their world by telling the story of Landon Wilson, who was kicked out the U.S. military simply because he is transgender.

Landon Wilson.

In 2011, repeal of "Don't Ask, Don't Tell" allowed gays, lesbians and bisexuals in the military to come out of the closet and serve openly. But the ban on service by transgender people continues, because it is based on military medical regulations that are not in sync with current thinking and clinical practice of the American Psychiatric Association (APA). A Department of Defense official told CBS News that the military healthcare policies regarding transgender individuals are intended to meet the needs of the military services, including the ability to deploy and serve in austere environments with limited access to medical care.

A 2012 APA position paper said, "Being transgender gender or variant implies no impairment in judgment, stability, reliability, or general social or vocational capabilities." The organization urged "the repeal of laws and policies that discriminate against transgender and gender variant individuals" and that "no burden of proof of such judgment, capacity, or reliability shall be placed upon these individuals greater than that imposed on any other persons."

Back in 2009, when Chaz Bono announced he is a transgender man, I realized that I - like most Americans - knew next to nothing about what "transgender" and "transitioning" mean. I confessed my ignorance to Mara Keisling, the Executive Director for the National Center for Transgender Equality, who generously schooled me, leading to "A Pro Bono Transgender Primer."

Six years later, transgender rights are a hot topic. And if we're going to have a meaningful national conversation, we have to start by understanding the vocabulary. As Keisling told me two weeks ago, "the simple way to really describe it is that transgender people are people whose gender identity, that is their internal sense of their gender, just doesn't line up with what the doctor told our parents when we were born." Keisling says being transgender is not a choice; people usually know from early childhood that something just doesn't feel right. And she explains that transitioning is a continuum that may or may not involve hormones or surgery. It can be limited to changing the sex listed on a driver's license.

Grayson Moore, who is transgender, looks on as Utah lawmakers considered a landmark anti-discrimination bill during a committee hearing Thursday, March 5, 2015, at the Utah State Capitol, in Salt Lake City. A landmark Utah proposal protecting gay and transgender individuals passed its test at the state Legislature Thursday when lawmakers on a Republican-controlled Senate committee offered their unanimous and at times emotional support of the measure. (AP Photo/Rick Bowmer) AP

Of course, it's a lot easier to change a driver's license than societal attitudes. Fortunately, the national discussion is increasing. For example, the hit Amazon show, "Transparent," created by Jill Soloway, is providing insight into the daily issues faced by transgender people and their families by following a father who comes out as a transgender woman. Landon Wilson told me it's important to understand the impact of transitioning on family and friends. He told me, "You know, that's something that I think that we often forget to emphasize. When people begin their transition, they are not the only ones transitioning. And it's easy to forget that, because it becomes so much a focus on your own personal development. But it's your family that transitions, as well. It's your friends that transition, as well."

As for changing the law and society, that is coming slowly. Last July, President Obama signed an Executive Order "prohibiting federal contractors from discriminating on the basis of sexual orientation or gender identity." But that didn't apply to the military. When the new Defense Secretary, Ashton Carter, was asked last month about transgender troops in an "austere" place like Kandahar, he said, "I don't think anything but their suitability for service should preclude them."

Does being transgender render a person unsuitable for service? Not according to a report one year ago by a commission established by the Palm Center, led by former U.S. Surgeon General Dr. Joycelyn Elders and Rear Admiral Alan M. Steinman, a physician. It found "there is no compelling medical rationale for banning transgender military service, and that eliminating the ban would advance a number of military interests, including enabling commanders to better care for their service members."

Given the arc of the current discussion, the eventual repeal of the ban seems likely. But every day the policy remains in place means another day of secrecy for the estimated 15,500 transgender persons in the military. For Landon Wilson, the hiding is over, but his plans have been shattered. He loved being in the military and hoped he would have a long career. For now, he's working temporary jobs and volunteering for SPARTA, an advocacy group supporting LGBT military members, veterans and their families. "If there's anything that the military has taught me," he said, "it's learning to adapt quickly. And sometimes you take what you have and learn to make the best of it." As the interview ended, I asked, "But if you had the opportunity to re-enlist?" He answered without hesitation, "I would re-enlist in a heartbeat. And I look forward to the day that it happens."