• Everyone thought my twins would be close, but growing up, they ran in different circles.
• They decided to go to the same college by chance, and I didn't expect them to be friends.
• But for the first time, they are voluntarily hanging out with each other regularly, and I'm happy.

As the mother of 19-year-old boy/girl twins, I've noticed that people's assumptions about twins are often wrong. To be clear, I'm sure some of the common twin myths apply to others, but so far, not mine.

The biggest misconception about twins? They're best friends who are constantly in each other's orbit, sharing the same brain. People assume that because they share a birthday, they must be alike in every way.

That's not the case with my twins. In fact, they are opposites. During their freshman year of high school, classmates were often shocked to find out they were siblings. My daughter is outgoing and extroverted, while her twin is quiet and introverted. One of their teachers, who had them both in the same class, remembered my daughter but not my son — not because he wasn't there, but because my daughter was so talkative.

But all that changed for the first time when they decided to go to the same college.

My twins didn't plan to go to college together

The latest presumption about them is that they planned to go to the same college. Again, this is a mistake. Their decision to attend the same school wasn't intentional; it just worked out that way.

Before they selected a school, I was sure they would go to different colleges. Their interests are vastly diverse, and they only applied to a few of the same schools, mostly because of the free college application offers.

So, when they committed to the same college, I thought: Maybe they will become the mythical twins I've heard about all these years.

I wondered if someday they might be best friends

While my kids were still gestating within my womb, strangers shared their twin dogmata. I'd hear some variation of, "They'll always have each other." In theory, that's a beautiful sentiment, but would it be true for my twins?

As they grew older, they began to spend more time apart than together, though there were exceptions.

One day, when my daughter was 6, she proudly told me, "We sat together on the bus today."

"Finally!" I said. "You've been taking the bus together for two years and never sat together."

"There were no other seats," she said. Ah, that made more sense.

This exchange pretty much sums up their relationship over the years. They've always been friendly with each other, but there was no magical twin connection. They share the same 50% DNA as any other sibling — the only difference is that they spent nine months living in close quarters. And according to the ultrasounds, that situation wasn't always ideal, with my son's head pressed up against his sister's. Maybe that's why they crave some independence.

I thought they would lead separate lives at the same college

At first, it seemed like their paths would continue separately in college. They chose different college dorms, different majors, and different friends. My daughter's room was decorated with lights, posters, pillows, and plants, while my son's room had little more than a bare concrete wall and a comforter. That, too, summed up their different personalities.

But then something changed. About a month into the semester, my daughter told me they had a plan.

"We decided to meet for dinner once a week," she said, "to try out restaurants in the city."

My children go to college in New York City, and since they're both foodies, this idea made sense. But I couldn't help feeling a small thrill.

Over the next several months, they explored Asian, Mexican, and Italian restaurants. But aside from their weekly dinner meetups, they rarely saw one another. As their shared birthday approached, I found myself wondering: Would they spend it together or apart?

"For our birthday," my daughter told me, "I booked a reservation at an Asian restaurant for us and some of our friends."

I was stunned into silence. It was hard to imagine that my babies, who used to run in opposite directions as toddlers, would now be planning something like this.

They are still on their separate paths but found a way to connect

Despite their differences, my twins have carved out a space for each other in their lives, even if it's not in the way people expect.

While I'm trying to taper my giddiness, I'm simply comforted, knowing that — despite the miles between us — they have each other.