I wonder what kind of guys we are talking here.
Then you are not the right girl for the guy who approached you. As simple as that.
I wonder how you would react in a club if some random guy came up to you and expresses his interest in you, because that is a normal thing there. If that is ok for you, then you are even more conservative as I thought. If not, then you are not into dominant and honest guys and you prefer needy guys.
In a club that's another thing, people go there to interact between themselves. But on a street it's a normal part of women's psychology to freak out. Since you're a little girl, they tell you not to talk to strangers on the street, and no matter what intentions you have, you are still a stranger and we cannot know what intentions you have. It's a learned code, nothing to do with being conservative or not, it's as simple as being taught to have 911 pre-dialed when walking home alone at night or to hold keys as a weapon, to sit alone and close to the driver on the night bus. Normally you would think it's nonsense and that you would never do that, but once being in that situation you suddenly find yourself holding the keys and pre-dialling 911.
If I lived in a safer country I would probably behave other way. But generally, if I told someone that a random guy spoke to me on the street and I went somewhere with him afterwards, people would think I was utterly stupid and incredibly lucky that I wasn't dead by now. Not trying to say that I couldn't meet a freak in the club, but also there any reasonable girl will try to find out if some of her friends know the guy before really going somewhere with him. Among my friends there are almost non who have a gf/bf who isn't somehow related to the others. They are always a friend of someone, a relative of someone, or they went to the same school as someone, you met them on the school dancing course etc. You rarely get to talk to someone you weren't introduced to by your friends here.