Forse ha il virus ma non ha sintomi, o non lo ha mai notato, o si è semplicemente dimenticata, succede molto spesso, o forse ti sei ammalato ad un certo punto e ti è venuto per conto tuo. ###>Maybe she has the virus but has never had an outbreak, or maybe she didn't notice if she did, or maybe she just failed to mention it, that happens all the time, or maybe you had a cold sore at one point and gave this to yourself.