If you've ever traveled alone then you understand: leaving your best friend to go home just plain sucks. You may have only known them for a few short months, maybe even a few short weeks, but the friendship you've built with them is more sacred than any you've ever known.

When the taxi pulls up to take them to the airport, you refuse to say goodbye. You hug them and make them get in the car before they see you cry. They take a piece of you with them to their home halfway across the country or halfway across the globe, and you somehow know that this friend of yours will last a lifetime. Nothing compares to what you two have together.

1. The best moments in your life include each other.

They were there when you journeyed to a mountain-top Temple to watch the sunrise over the Himalayas. They were there when you hiked barefoot to the city look-out and when you rode in the back of a truck to swim in a mountain stream.

2. You teach each other things.

I can say "peach" in Dutch, how 'bout you?

3. They love you for who you are in the present.

The people you meet while traveling know the REAL you. They have no preconceived ideas of your personality or lifestyle. They have no expectations for how you should think or speak or act. They don't know your past, your pedigree, your baggage, or even your major accomplishments. They meet you, accept you, and come to love you in your purest form, when you're free of everything that clutters your normal life.

4. You've been through highs and lows together.

They've seen it all: they were there when you ran out of money and couldn't find a working ATM, and they were there when you had a total epiphany about your life's purpose.

5. They give you a new perspective.

My best friend grew up in the Netherlands, and I grew up in the United States. Meeting her was like meeting a kindred spirit, a long lost sister, my other half. But we grew up in different worlds, and watching her was like seeing myself view everything in a slightly different light.

6. They teach you to find similarities and appreciate differences.

Certain things in the human experience are universal: love, death, time, joy, sadness. You connect by sharing in these things. But what's even cooler is how you grow by learning to understand the ways their different backgrounds have taught them to feel, think, and talk about things like love, joy, and sadness. You love them for how different they are, for what they can teach you and what you can teach them, and for how they feel like they are your other half.

7. Those things only travel friends understand.

You were both weird, misfit, outcast foreigners together. You tried all the local food together, and you searched high and low together for a place that could give you your American food fix. You struggled learning another language together, and you hid away in a hammock together when you just needed to be able to speak a little English. They were your rock, and you were theirs.

8. They broke you, and they healed you.

We uncovered trauma, we talked about our futures, we battled eating disorders, we lost and found religions; we discovered new parts of ourselves. Travel has a funny way of both wrecking you and putting you back together, and your travel friends are there with you through it all.

9. They help you be your own hero.

When you travel, you're away from your friends, your family, your significant other. All you have is yourself. You have to learn how to fend for yourself, fight for yourself, know yourself, love yourself, heal yourself. And your travel friend is there with you the whole time, encouraging you. They know exactly what you're going through because they're going through this same journey, side by side with you.

10. They were everything you needed.

They'd invite you over to dinner, and you'd invite them over for sleepovers, and you practically lived in each others' houses. While abroad, somehow they were your family, your significant other, and your best friend all in one. You leaned on them for love and support. Besides yourself, they were all you had.

I miss overeating Magic Masala potato chips and dried mango in bed with Rosan in India, watching seven minutes of a movie at a time because our wifi could only handle so much. I miss making pulseras and reading in the hamaca with Sara in Nicaragua, blowing bubbles to the little kids and feeding last night's tortillas to the stray dogs.

Our globe-trotting adventures have been replaced with periodic Whatsapp messages and semester-ly Facetime dates. We hold the sweet memory of each other in photos, journals and stories. I think of them every time I taste mango or coconut, or when I wear that dress or bracelet they gave me. And I dream of meeting them again, a decade or two from now. We'll travel together to Thailand, or maybe one day I'll have a layover in one of their home towns. My heart is full knowing that, even though they are oceans away, I have a forever friend.