Traingazing

Sonder
n. To realize that each random passerby is living a life as vivid and complex as your own

Fantasize
'fantəsʌɪz
verb | To indulge in daydreaming about something desired.

And two strangers allow each other to do just that when they meet due to happenstance.

Or

Where two perfect strangers meet at two perfectly strange places and wonder what it would be like to belong to each other.