"Best hint - go with the flow, let the adventure happen, don't rule anything out and get involved rather than beng an onlooker."

But be careful! I narrowly avoided being badly conned in Athens a few years ago. I'm not saying this sort of thing is peculiar to Greece - it could happen anywhere. There are some nasty and unscrupulous people out there who prey on tourists because they know that they tend to have their guard down.

Having said that I had other encounters in Athens which were, hopefully, more typical of Greece. That is encounters with charming and hospitable people who made me feel very welcome.

In brief, be very wary of what appear to be chance encounters with over-familiar people in very touristy areas.

Oh yes, a more general piece of advice, that can't be repeated too often, and doesn't just apply to Greece: keep your valuables out of sight - particularly your money and your passport.
Three of my friends have been robbed recently - in Fiji, Latvia and the USA (and the authorities were very unhelpful).