Many moons ago, if you happened to see a nice girl, it would take many weeks of "hanging out in the same area" at different times of the day, hoping that chance would intersect your paths again.
You would ruminate on that memory of her fading in and out of your view. You would keep guessing and imagining who she is, what she does and what kind of music she prefers.
And maybe... maybe, if you were a good guy (take the trash out, keep the house clean, do your homework and help your neighbors), the planets would align in your favour and you'd get the chance to have another glance at her fair face.
***
All you have to do today is sift your friends' photographs and look for that charming smile.
You will shortly find out her name and see that you have 19 friends in common. In 10 minutes you will know which other countries she visited, which movies she likes, where she studied, where and with whom she works.
If you get lucky (I did), she'll show up at the top of your news-feed, tagged in the photo of someone you know.
After a few more clicks, you might even see a pic of her handsome boyfriend and discover that she's friends with the people you were in a relationship with :-)
Welcome to the present! Mwahahaha!