(Charles Dharapak/AP Photo)

If Staff Sgt. Jonathan Mills wants to get across one message about gay service members, it’s that “We haven’t just popped up today, we’ve been here all along.”

Mills is a gay active-duty service member in the Air Force who can now serve openly, thanks to Tuesday’s final repeal of the “Don’t Ask, Don’t Tell” (DADT) law.

The 18-year-old law prohibited gay service members from serving openly in the military, and was officially repealed Tuesday at 12:01 a.m.

Mills said the most common misconception about gay service members is that “we all seek to invade each other’s privacy,” and that “sharing is going to be a problem.”

Questions about whether gay and straight service members can share showers or sleeping quarters are disingenuous, he said, because “gays have been in the military all along.”

Prior to the repeal, Mills was forced to evade answering simple questions by co-workers, such as “How was your weekend?” or “Whom did you spend the weekend with?”

He said gay service members would often have to ignore those questions completely, deflect, or lie — which built distrust with coworkers very quickly.

But on Tuesday, Mills came out publicly, speaking at a press conference on the Hill.

“Today I feel extremely elated,” he told ABC News on Tuesday. “A heavy load has been lifted. I’m really grateful that our Congress came together to work to repeal this law.”

Mills also serves as executive editor for OutServe magazine, which just published a special edition Tuesday also at midnight, featuring “101 Faces of Courage” — 101 service members who can now speak openly about their sexual orientation.

Mills said that so far, friends, coworkers and supervisors have been extremely supportive, texting him and calling to say congratulations. He said he plans to bring a male date to the next unit function.

Mills said he believes repeal of the “Don’t Ask, Don’t Tell” law will not have a huge impact on the day-to-day level, but will have a huge impact on the strategic level.

“Some colleges and universities — including major ones — barred the military from coming on campus and recruiting,” he said, due to DADT. Now that it’s repealed, Mills predicts an influx of recruits, which will lead to a larger and more qualified pool of candidates.

A ribbon-cutting ceremony took place Tuesday afternoon to celebrate the opening of a Naval Reserve Officers’ Training Corps (ROTC) office at Harvard University, according to the Harvard Crimson. ROTC was previously banned from the university because DADT violated Harvard’s anti-discrimination policy.

Mills said his only reservation with the repeal is that there is always the possibility of any of his fellow gay service members having even one negative experience.

“We all received repeal implementation training,” he said, predicting that any problems will still be looked at on a case by case basis. “But as a rule, commanders will not make exceptions for [complaints such as] sleeping arrangements. It’s not a valid consideration.”

At a press conference today, Defense Secretary Leon Panetta said the military would have “zero tolerance with regards to harassment.”

“My hope is that the command structure operating with the standard disciplines that are in place will implement those disciplines and will ensure that harassment doesn’t take place and that all behavior is consistent with the discipline and the best interests of our military,” he said.