There have been many times in my career when I was the only woman in the room; if I didn’t speak up, it was often noticed. I found speaking up took practice, but over time it became an important source of growth in my career.

One moment occurred during my freshman year of college. I was 16 years old and taking my first government class. Midway through the lecture, the professor introduced a bizarre theory as if it was a matter of course: Black people are born with lower IQs than white people. Everyone – including the black students – just sat there, accepting his theory as fact. Meanwhile, I was a 16-year-old black woman in college who spoke two languages and could play Beethoven and Bach on the piano. I was stunned, not only by this absurd statement, but by the lack of reaction from the other students. So I raised my hand.

The professor was stunned that I chose to speak up, and seemed even more amazed when I showed up the next day to argue the point. After that day, he realized his mistake and attempted to befriend me. I went on to excel in the course, despite the obstacles. I also learned a valuable lesson: If you find something uncomfortable or wrong, speak up. If you don’t challenge people, you aren’t doing your job.

In 1984, another situation arose that challenged me to speak up once again. I attended a seminar at Stanford featuring the then-National Security Advisor, who spoke on a commission I felt very strongly about. His mealy-mouthed answers caused my blood pressure to rise; yet no one pressed him for further information. So I raised my hand and shared my perspective. He seemed surprised, yet also impressed. Later he approached me and we talked. He noted my willingness to speak up and praised my thought process. That moment led to a life-long relationship, with him acting as an early mentor.

As my career evolved, so did my desire and need to speak up. Early on in my role as the National Security Advisor, I often had the opportunity to present options, but rarely did I ever voice a strong opinion in front of the President.

One afternoon, I found myself in a heated debate over President Bush giving a speech on the situation in the Middle East. It was a violent time, and there was concern that the President’s speech would only exacerbate the situation. I knew the President wanted to give the speech, so I decided to speak up. I said, “Mr. President, sometimes the only person who can make an impact is the President of the United States. You have to do this.” I waited for his response, nervous that I had overstepped. Instead, he smiled and agreed. He gave the speech and it was a rousing success.

It would be easy to say I have always spoken up at the right times. However, there were definitely moments in the first term of the administration when I took a more traditional role and chose to remain silent. In retrospect, there were many points I should have raised; I could have gathered my thoughts and gone directly to the President.

Learning to speak up is a valuable lesson. As women, we must never be surprised that surface equality isn’t actual equality. Society still very much plays into gender bias and role definition. When a woman walks into a room, people see a female. For some, this indicates what she is capable of achieving. This, however, should not deter you. If you spend all of your time thinking about how you are viewed, you will lose your ability to be effective. Walk in, embrace your job and do what you’re supposed to do. If you are young and disadvantaged, find a mentor who can help you through the experience. If you are senior in your career and you allow someone to treat you poorly, it’s your fault. You have plenty of weapons in your arsenal: use them. At some point you have to lean in.