Is it normal i stand up when i eat ? it really bugs my mom .

IS it normal I eat standing up , I dont know why I do it apperently most young poeple do it I think I developed this habit becuase when I useta go to lunch at school I never went anywere , were thier was tables we kindve just hung in a big group and just stand around somewere and talk . I still do this I do this all the time . I do this when I cook food for myself and ill stand in the kitchen at the counter and start eating I wont even sit down I just stand their course I sit sometimes but for some reason my mom gets so peeved by this i dont understand why this bothers her . Anyways is this that odd my mom says all the kids she sees do it and she doesnt understand why any of us do that is it really that odd ? Im not living my mom anymore but she finds it bizarre I never sit anywere