( CNN ) -- I still remember the chill that came over me the day my middle school history teacher showed the class a documentary about the Holocaust . Millions of Jews were systematically isolated , corralled and eventually murdered by the Nazi regime . It 's a horrible blemish on the history of mankind , one that is rarely brought up lightly . It 's one that is recognized in museums , dramatized in film and taught in middle schools like the one I went to nearly 30 years ago . And yet , despite my continuous exposure to the retelling of the Holocaust , it was n't until I was in my mid-20s that I learned Hitler had also isolated , corralled and murdered gay men and lesbians during this time as well . Right now I can hear the voices ask : What does it matter ? I had graduated from high school before I learned some of the greatest voices during the Harlem Renaissance and civil rights movement -- Lorraine Hansberry , James Baldwin , Bayard Rustin -- were members of the LGBT community . It was in graduate school when I first heard the name Harvey Milk . I was a working journalist before I was told about Dave Kopay , the former NFL running back who came out in his 1977 autobiography , `` The Dave Kopay Story . '' And now the chorus of voices ask : So what ? Over the years , I am proud to say I have amassed a decent personal library . Most of the books are about history : presidential biographies , wars , social justice movements . And yet , it was only this week -- thanks to longtime civil rights activist David Mixner -- that I learned Congress once debated passing a law forcing gay men to wear tattoos and corralling those who were HIV positive into internment camps . Yes , just like the Jews . Just like the gay men who were next to those Jews in Nazi Germany but have since disappeared from our history books . It is here where the cynic wonders : Who needs to know ? With the overturning of `` do n't ask , do n't tell , '' the sweeping changes in marriage equality , the presence of open LGBT people working in the White House , on TV , even in professional sports , there may be some who believe the heart of homophobia no longer beats . Much in the same way others believed the burning of bras slayed sexism and the election of President Barack Obama was racism 's death knell . One of the most powerful CEOs on the planet has announced he is a proud gay man , and while I may be hesitant to characterized Apple 's Tim Cook proclamation `` brave , '' it is nonetheless important . He is here . Just as Hansberry and Rustin and Milk were there -- working for the greater good , changing the course of global history , woven into the fabric of humanity . The voices may ask : What difference does it make ? Let the absence of LGBT people in our retelling of our history be the reply . For if being gay , lesbian , bisexual and transgender truly did not matter , why then must we fight to have our contributions recognized ? Why then , when California became the first state to require our stories be included in the history books , was it met with resistance in 2011 ? That conservative state Assemblyman Tim Donnelly described the day the bill was signed into law `` sad '' as if simply learning that a group of people existed infringed upon his Constitutional rights . To be honest , Cook 's announcement is no great shock to anyone who has been paying attention to the rumor mill . But by owning his truth in such a public fashion , Cook is not only rebuking the tendency many LGBT baby boomers still have to hide , but he is also refusing to allow his silence to render him hidden . When the middle school history teachers speak of him , they will have his full story to share . Going forward , chants of `` who cares ? '' will accompany nearly every person of note who chooses to come out publicly . Even among LGBT people , shoulder shrugs will not be that uncommon , as if debates about internment camps happened in the 1880s and not the 1980s . Yes , the country is different , and being gay is no longer shocking . But it is a mistake to confuse that progress with Cook 's announcement having no importance . For far too long , the story of the LGBT community has been scrubbed from our education , contributions erased and existence relegated to the poorly lit corner of bookstores under the banner `` Alternative Lifestyle . '' We are not a `` lifestyle . '' We are a people , and we were there . And we are here .
LZ Granderson was an adult when he learned gay people were also Nazi victims . He also learned key figures of the Harlem Renaissance , civil rights activists were LGBT . Why does it matter ? Granderson says it 's crucial gay people not be erased from history . It 's important to know the full history of people such as Google and Tim Cook , he says .