You’re walking down the street and there’s a man trailing uncomfortably close behind you. A co-worker stands a little too intimately in your personal space. There’s a stranger breathing down your neck on the subway. Each time, you do a quick mental arithmetic: Do I ignore it? Move away quickly, but without causing a scene? Say something? Yell?

“This is not O.K., I thought,” Hillary Clinton writes in her forthcoming memoir, “What Happened,” in a passage to which too many women can relate. “It was the second presidential debate, and Donald Trump was looming behind me. Two days before, the world heard him brag about groping women. Now we were on a small stage and no matter where I walked, he followed me closely, staring at me, making faces. It was incredibly uncomfortable. He was literally breathing down my neck. My skin crawled.”

In excerpts from the book, which were released by “Morning Joe” on Wednesday, Mrs. Clinton revealed that in that moment, she asked herself: What do you do? “Do you stay calm, keep smiling and carry on as if he weren’t repeatedly invading your space?” she writes. “Or do you turn, look him in the eye, and say loudly and clearly: ‘Back up, you creep, get away from me! I know you love to intimidate women, but you can’t intimidate me, so back up.’ ”

Mrs. Clinton did what most women do when they face harassment or intimidation: She ignored it. But now she’s stewing in the what-if:

“I chose option A. I kept my cool, aided by a lifetime of difficult men trying to throw me off. I did, however, grip the microphone extra hard. I wonder, though, whether I should have chosen option B. It certainly would have been better TV. Maybe I have overlearned the lesson of staying calm, biting my tongue, digging my fingernails into a clenched fist, smiling all the while, determined to present a composed face to the world.”