.... the world was in fact bigger than you thought it was ?

Let me explain :

I was talking with a friend yesterday evening about when you're 7-8-9 years old, in fact that's the age you realise the world is not only just your country or town etc .... I find this subject very interesting. More again because we are from all over the world on jt.
In general it's because of an event in the actuality (sad in most of the case unfortunely).
He told me for him it was the construction of the wall in Berlin, and for his son, it was the events in NY.
For my son i guess it's the recent events in Madrid ... he keeps asking lots and lots of questions about this.
Honestly i can't remember what was it for me ....
I'd like to know what was it for you ? what made you realise there are other countries and people in the world ? (hope it's clear )
Maybe it will help me to remind what it was for me too .....