"like him that travels I return again" sonnets cix

My need to rant about things has encouraged me to pick up this blog, two years later. For a while I just didn't really have anything to say, but a reoccuring experience I've had in the last few weeks has left me feeling the need to throw my thoughts out into the ether again.

So here's the scenario: I'm walking down the street, just a normal stroll to run some errands. I pass by a dude, and happen to make brief eye contact. The dude goes, "Hi." Now, I don't know the guy, but I also don't want to live in a world where people can't just say "hi" as they pass on the street. So I say "Hi," back. Not in an inviting way, just in a, hey, we're two human beings passing on the street kind of way.

Then the guy says something to the effect of "you look really nice" or the like. Nothing lascivious, nothing inappropriate, but by actively commenting on my appearance, now we're pushing the bounds of personal space, I feel. However, at this point, all he's done is say hello and then paid me a seemingly ok compliment. So, not wishing to be rude, I say, somewhat brusquely but not rudely, "Thanks," and continue walking.

Apparently accepting this compliment is construed as an invitation. Now the guy says -- and this is verbatim, and has happened in exactly these words three times recently -- "Can I get your number?"

OK. So, we went from, let's be civil, to ok you're a little forward but haven't said anything actually objectionable, to, completely unwanted advance.

So where should I have stopped this? I don't want to be someone who scowls whenever someone I don't know tries to speak to me. I want to be open minded, not pre-judge people, and engage with the world around me. But what should I have done differently to avoid the unwanted advance? I don't want to not say hello to someone when they say it to me. When they pay me a compliment, as I said, it's an unobjectionable one, but should I scowl at that point regardless, now that prior experience sets off the alarm bell?

This may be partly a case of the "nice girl" syndrome -- perhaps I don't want to be perceived as not a nice and pleasant girl, lest I be judged not feminine, etc. -- but I really think it has more to do with a desire not to shut off from the world around me because of a few bad apples.

I'm curious what others think about this ...