I am still in the beginner phase of this but have been approaching more girls in the last couple months than I have in my whole life...

I approached this cute girl in Barnes & Noble and she was refreshingly receptive, she said she recognized me which kind of freaked me out, it's possible I could have approached her before and so I asked her that, and she said no and that she recognized me from where I work. My instinctual response was 'Oh so I probably shouldn't do this because you know where I work', she replied 'Wait why? Why is that bad?' We were both kind of confused and I'm not exactly sure why I said this. Any ideas as to why I said this? I thought it might be feminism: shaming boys into being sexually attracted to girls and wanting to bang them... I've constantly read on here that you shouldn't hit try to pickup girls that you work with. But a girl who just recognizes me from work isn't bad is it? As long as I respect her boundaries I should have nothing to worry about right?