I just saw a movie "Before Sunrise" wow, it was almost painful to sit through...it so accurately captures those moments that every traveller encounters when they travel alone in an alien environment...
where you meet and have an instant connect and amazing rapport with a complete total stranger who you only came to know as you were in the same place at the same time....a chance encounter that had like a one in a zillion chance of happening...
The worst part is you both have your own separate lives to return to very very far apart in geography and that heavy feeling in your heart is that you know you can just enjoy the present moment and then have to say Goodbye never to see that person again. That it was a transient encounter that you have to let go and forget about to spare yourself the pain of separation. The challenge (especially for females) is always about not getting emotionally attached...
And even if you are foolish and try and keep in touch, the timezones and daily life opposite to your own and your responsibilities back home in the with the passing of time get the better of you, so it is actually easier to not even try and just accept that it was a nice moment, that it is what it was. And that's that!