If someone told you to 'be careful' as a farewell...?

My mom used to say that all the time to us kids and other people as well. I guess everyone took it differently, one lady in particular she said it to always acted like my mother was trying to tell her to not take any risks or not live fully to avoid any danger which is not the way my mother meant it. I would just take it as that person may have lost someone they love in a freak accident (as inmy mothers case)and they care about you so don't forget it.