My mom used the same justification- she wanted me to be "realistic." That was her excuse for all the verbal and emotional abuse she heaped on me for years.
In my twenties I realized that she is mentally ill (paranoid schizophrenia). She also suffered horrific physical abuse as a child, so as long as she wasn't hitting us with her fists she thought the verbal lashing out was fine. She used to tell us all the time how lucky we were and what a soft, easy life we had.
My childhood sexual abuse was swept under the rug and she alternates between claiming not to believe that it happened at all and telling me to get over it and stop being a manipulator trying to get others to feel sorry for me.
I am able to have a better relationship with her than I ever have before. I keep it cordial and superficial, never sharing anything deeper than the surface stuff. When she has a psychotic episode and turns nasty I cut off contact for awhile.
It is hard not to take those things personally or to somehow feel like you've done something to deserve it, but your mom's behavior was never your fault. Understanding my childhood trauma has helped me in my own recovery from bad relationship choices as an adult. I picked people who had the same qualities as my parents and inevitably ended up hurt.
Thanks for sharing this. You are not alone.