In the park

Hallelujah! Finally the sun has come to Brussels. I wandered out to the park with book and iPod and settled down with my back against a tree to read a little and daydream a lot.
After about half an hour, I heard 'Excusez-moi' from over my left shoulder.
- Excuse me, said the guy, 'can I sit down with you? Maybe we could talk for a bit?'

I got up hurriedly, gabbled that I had to meet someone and rushed away.

But... as I was walking away, I wondered why I was so reluctant to talk to the guy. He was perfectly polite, he seemed clean and didn't look particularly odd in any way. He had tanned skin, dark hair and a strong accent: perhaps it was a case of a deep-seated racism I was hardly aware of? I slowed my pace and started to think it through. If the guy had had blonde hair, would I have talked to him? Had I ever dated a guy who was not a white European? If I had been approached in the same way by a woman, would I have found her as threatening?

I thought about how many intriguing conversations with fascinating people I was missing out on by refusing to speak to strangers in the park (on the train, in a cafe, etc). After all, isn't that how most romantic comedies start? Boy bumps into girl at random and conversation starts?

A few years ago, I went on an Erasmus exchange to Trento in Italy. I remember, six months earlier, having returned from a worthwhile but often disappointing assistantship at a small town in Brittany and I was determined to do it better this time around. As I strode out of baggage reclaim, chin held high, I decided that this time, I would be completely open to new experiences: I would talk to everyone.
I struck up a conversation with the woman sitting next to me on the airport bus (clearly a backpacker). It didn't hurt one bit. I was encouraged.

I only spent five months in Trento, but in those five months I learnt to ice-skate, snowboard and read mediaeval musical notation. I ate Melinda apples in the Val di Non; drank Fragolino in Verona; bought fresh pastries from the bakery window before dawn on the way home from a night out; accepted lifts to concerts on impulse; spent long, lazy afternoons sunbathing with my flatmate in the park behind the flat and long, lazy evenings cooking huge, slow pots of pasta with friends and drinking litres of red vino da tavola. I gained a few kilos and near-fluency in Italian (both of which I subsequently set about losing).

What do you think? Do you talk to strangers? Where do you draw the line between a harmless conversation on the train and something more threatening? When would you stay and talk, and when would you up sticks and leave?

I'm curious: just how far should I trust my instincts?