I remember nothing about my accident earlier this month — from the time I opened my front door to take the dog out at 9:45 in the evening until many hours later when I regained consciousness at the emergency room. Upon waking up, I had no keys to my apartment, no identification, no clothes but the bloody nightgown and trench coat I was wearing, no cell phone or contact information, and no clue where the dog was, although I assumed he’d most likely been run over by car.

I also had no idea what hospital I was in, until my brother arrived, and then couldn’t remember what he told me and asked him over and over. Mostly, I didn’t care, wanting only to escape the bright lights and cacophony of the E.R. and sink into the oblivion of sleep, which of course was impossible.

The curtains of ignorance parted ever so slightly when Michael returned to the hospital the next day. He had been to my apartment building and solved some, if not all, of the mysteries, many of which will likely never be clarified. Much of what he told me, within minutes, was erased from my mental circuit board.

But one thing stuck: I had been saved, and so had the dog, because of the kindness of strangers, even in this city thought to be so heartless. A native New Yorker, I never believed that cold stereotype, but neither did I have first-hand proof of its foolishness. Now I did.

My brother, also a journalist, knows how to find things out and is notably cool in a crisis, unlike his hyperventilating, weeping older sister. While I breathed into a paper bag and tried without success to gulp back tears, here is what he told me: The owner of a corner restaurant had found me, lying between two pools of blood on the sidewalk, and he wrapped my head in a kitchen towel — the first in a series of what seem like miracles. At just that moment, a neighbor whom I barely knew exited the building and took over.

My neighbor called 911. He took me into the lobby where it was warm and dry. He tolerated my abusive insistence that I would not go to the hospital and told me it wasn’t my choice. He asked what had happened, and I mumbled I’d gotten very dizzy. Then, by his account, I again disappeared down the rabbit hole of unconsciousness, as the building superintendent helped the paramedics load me into the ambulance.

With the self-possession of a man who had recently lost an invalid wife and had two teenage daughters, he noticed and scooped up my keys from the street, walked my dog (who had sat by my side licking my face the whole time) and took him upstairs. There, the door unlocked and the television on, he searched my cupboards until he found food for the dog.

He also noticed my cell phone and address book on my desk. That’s where he found my brother’s phone number, although I didn’t realize he even knew I had a brother. He locked up the apartment and took my keys with him, after making plans to give them to Michael the next morning.

Did I mention that, at some point, he went back downstairs and took cell phone photos of the blood on the stoop, thinking it might help the neurologists understand what had happened? Since I’m a techno-idiot under the best of circumstances, once I was home from the hospital, he helped transfer the pictures from his phone to mine for show-and-tell as I made the circuit in the following days from neurologist to internist to neurosurgeon.

Only because of him did the follow-up doctors know that I’d walked down a marble flight of stairs, across the lobby, and out the double front doors before falling to the ground. They were able to surmise I’d fainted, and not had a seizure. All this, in the E.R., had been a mystery to the doctors and nurses.

In the days since, my neighbor has stopped by regularly and sends frequent texts and calls. A week ago, the only thing I knew about him was his first name, that he lived in apartment 2-F, and that his wife had recently died a long, slow, and terrible death just days after their younger daughter had left for college. I had struggled with a sympathy card because I didn’t know his full name, or his daughters’, so I wrote a vague salutation and pushed it under the door rather than mailing it. Now my troubles and his kindness have forged a friendship that extended to his offering me his wife’s shower seat so I could safely wash the matted blood out of my hair.

My upstairs neighbors have sent me their cell phone numbers, told me when they are going to be in and out of town, and delivered a Chanukah present — appropriately, a key ring with a doggy charm. Someone from the fifth floor whom I don’t know at all left a commiserative card. The superintendent looks in from time to time, and I know he would bring me food if I hadn’t hired home health aides for a few hours each day to take me to medical appointments and stock the refrigerator.

The home health aides alternate days, and each calls and texts in between to check up on me. One of them, originally from French West Africa, was a doctor in her homeland. Now she empties bedpans and sits up all night at the bedside of people with Alzheimer’s disease while a babysitter cares for her two toddlers. Soon she will start nursing school. Who among us middle-class and native-born knows for sure they would have such fortitude?

My brother’s diligence and love continues, as do my friends’. But all must live their lives, do their jobs, and not feel the duty to be here with me. So at this lonely and scary juncture, it is the kindness of strangers that has soothed my soul. Now it is my job to pay it forward.