• 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.

• When traveling home from college for the holidays, my son went to the wrong airport.
• I knew I had to teach my college-age kids some important travel tips.
• I now make them buy their tickets and ensure they have pictures of their IDs.

My 19-year-old twins are experienced travelers. Since they were born, we have traveled internationally and domestically on every form of transportation. So last year, when they were college freshmen and traveled for the first time without me, I assumed it would go smoothly. Well, you know what they say about assuming.

The Thanksgiving flights to and from college went OK since they traveled together. It was the December break when one of my twins had an issue.

Since their last final was a week apart, they decided to fly home separately. I had booked their airfare since I had airline miles. I sent my son the ticket and told him all the information, but he must not have been listening.

When he got to the airport, he tried scanning the ticket, but it didn't work. After calling home, I realized he was at the wrong airport. He went to the same airport he flew from for Thanksgiving without knowing there were two airports in New York City. He took a $80 cab ride to the other airport and made his flight, but that was a costly and nerve-racking mistake.

We learned a lot that first year, so I was forced to teach my college students these five tips so they could make it home safely for every holiday.

1. Let your college student book their own tickets

When I told other parents about my son's travel mishap, they suggested that my kids book their own transportation. Not only will they pay better attention to where and when they are traveling, but this will also help them be more responsible adults who are less dependent on their mom.

An added benefit is that they will be more mindful of the cost of travel. That's all part of the college experience, right?

2. Take a picture of their passport or license

My twins have photos of their licenses and passports on their phones in case they forget or lose them. So far, they haven't, but it's helpful to have a backup.

I've also taught my kids a few important lessons about identification and traveling: First, always do a 360-degree sweep of any area before you leave. For example, if you are getting up from your seat in the waiting area, you should turn around and search the area before moving on to the next one.

Another suggestion is to check for important items like your wallet, ID, and phone several times while (and before) traveling.

3. Tell them to arrive early to allow for mistakes

When my son went to the wrong airport, he made his flight mainly because he got to the airport two hours early. The other airport was over 45 minutes away, so he didn't have much time, but it was enough to get there.

The flights at both airports were full, so I don't think he would have been able to fly that day if he didn't make that flight. Arriving early helped him correct the mistake and catch the flight.

4. Discuss safety tips when using ride-shares

So far, my twins have taken their college campus van to and from the airport. This is a safer and less expensive option than rideshare since the college has vetted the drivers who are college students. Your college student can check with their school to see if they offer similar transportation options that might be safer and less expensive than public ones.

The one time my teen took the cab, I discussed safety issues like checking for an ID and asking about the cost and forms of payment. I've also discussed the importance of being aware of your surroundings and keeping your valuables secure.

5. Discuss all travel rules beforehand

Since my twins fly and don't check luggage, they can only pack drinks that are 3.4 ounces or less, and I remind them about this to avoid issues. I don't want them panicked at the security line when they're told their toiletries are a violation.

If my kids are prepared and know everything they need beforehand, I hope their travel back home can go smoothly.

Hopefully, these tips will help your college student arrive home safely for the holidays and avoid costly mistakes.