I began my life in a rather selfish, self-destructive manner. Sharing a womb with my identical twin sister, I decided to hog the majority of blood allotted to us, so much so that she was born white as a ghost and I beet red. She never really begrudged me this selfishness, or any of the other selfish acts I’ve done over the years. Maybe I don’t recognize that enough.

Getting closer to Thanksgiving, I have been thinking about what I am thankful for. Family, naturally, came to mind. Then I remembered one of my professors a semester or two ago mentioning how little I write about being a twin. My excuse then, and now, has always been that being a twin is such an integral part of who I am that to separate it enough from myself to clearly write about it and its effect on me would be nearly impossible. But I suppose it is time to give it a go, and just in time for Thanksgiving.

So what is it like to be a twin? In the most simplistic terms, I have never been alone. Sure, we’ve all experienced loneliness, but being truly alone is an entirely different manner. Honestly, I can barely comprehend the concept.

Except for maybe a total of one year, I have lived in the same room with my sister for 21 years. We’ve slept in cribs, bunk beds, trundle beds, bunk beds, twin beds, and queen beds. Except for the cribs, each set of beds brings with it dozens of memories, and this largely contributes to why I do not merely have a twin sister, but why my twin sister is one of my best friends.

As children, there was always someone else in the room when the dark was a little darker than usual. As preteens, we learned how to stay up later than Mom would let us as we read by flashlight, side by side. We stayed awake together the first night our new step-dad spent the night at our house and snored loud enough to cause concern. As our bedtime became gradually more relaxed, and eventually disappeared altogether, we read books side by side through the night or binge watched Gilmore Girls before binge-watching was cool. And we talked.

We would eventually decide to go to sleep, since we were not yet in college and did not have entirely self-destructive sleeping habits, and after the lights were out and silence pervaded the room, one of us would start talking. Despite droopy eyes, despite the hour, despite our mom’s occasional reprimand to go to sleep, we would talk about anything and everything. No part of our day was too insignificant. The few parts of the day we had not spent together were relayed, in excruciating detail, to the other. These conversation would often lead to laughing fits that left us breathless. Or to pillow fights—both violent and fun ones.

I can’t even comprehend living life without that outlet, without that piece of life where everything else was silent and no topic was off limits. These somewhat meaningless conversations connected us as twins and friends more than blood ever could.

So what is it like to be a twin? It is being practically the same person for the first half of our lives. It is growing apart into our own persons, and loving our differences. I’m better at school and better at books. She is better at dealing with people, especially with children. I love my long hair and jeans. She loves her short hair and dresses. It is seeing her become one of the most true and authentic people I’ve ever know or heard of, and loving her ability to be the person I could never be.

We have been together for every obstacle in each other’s lives, most of which we have shared. I know her, and she knows me. We used to joke that it would be difficult to grow up and find a husband because they would somehow have to equal or surpass the level of comfort and familiarity that we have built over decades. (By the way, the current perfect plan involves a double wedding—with the only thing hold up being to actually find the guys. Details.)

It is easy to take a twin for granted, because they have literally always been by your side. This is a rather weak description of what it is like to have an identical twin sister who also doubles as my best friend, because it is a lifelong experience that has reached into every aspect of who I am.

So this Thanksgiving I am thankful first that I am a twin, but more importantly for the woman who is my twin and the person she has become.