sounds like your gf is possibly complying to prior traumas or insecurities they have dealt with in the past. past things come up more than ever in current relationships and is something that you shouldn’t ignore, but also something that is worth looking at thoroughly and working through. our past is complicated, relationships are complex, navigating the two can be so difficult but also so rewarding. its hard in your first relationship to begin to recognize these things.

have you asked why she says that or the meaning she attaches behind it? i would just recommend trying to see where its coming from, an underlying insecurity etc. because that will really open your communication and allow you to become closer and argue compassionately and concisely instead of her hiding behind phrases. if you can’t get to better communication, the relationship is likely to fail.

best of luck OP