I'm never nice to this girl, why is she so nice to me?

I went out with this girl a few times, bought her breakfast and took her to a few sporting events. Things i was doing regardless and brought her along. We hooked up. But i'm never nice to her, i mean i act extremely straightforward and tell her exactly what is on my mind. I have even told her i didn't feel like seeing her one day and i would talk to her later. Am i doing something right for a change?