Is it normal to not know if you were abused as a child?

Yes, that's very normal because you don't really know anything different.

Even if you know that it is abuse and it is wrong, it's not until you start to thoroughly compare your upbringing to others that you begin to realize just how abnormal it really is.

Yes. You were absolutely abused. If there was evidence of this brought forth to authorities when you were young, your mother would have faced consequences for her actions. Even our own corrupt justice system frowns upon hurting children.
You'll learn as you grow that this isn't acceptable and children DO NOT grow up to be 'better people' by following those particular footsteps of their parents.

Just don't take in too much information about your mother at once- it'll hurt a lot. Take baby steps.

You were abused.

I understand your situation. I grew up in a home with violent parents and until I told a close friend and a relative, I had absolutely no idea that what they did was anything but normal behavior from parents to children. Now I know better, but it is difficult to considering "normal" is usually defined by where you grew up.

you were abused. some parents just don't know how to raise kids. i was also raised similarly, with negative reinforcement, which did NOT work, it just made me not want to do whatever i was told. if they had just used positive reinforcement and/or talked me through why they wanted me to do things and shared their personal experiences to get ME to want to do it, instead of just resorting to physical and verbal/emotional abuse, i would have done anything they said.

Your mom definitely abused you. I'm sorry. *hugs you*

I agree with most comments. Another reason for not remembering it is that sometimes when something traumatic happens to people, they just forget about it.
I'm sorry for what happened, you should try to forget this and if it really bothers you, try to find a good therapist or psychologist.

I don't find this to be normal.

Not remembering any bruises, doesn't mean that there weren't any. To not remember painfull events or the "consequences" of these is a typical sign of a (psychic) trauma, in fact not remembering could be a sign of PTSD. I don't know in which country you live and whether there is free health care, but i would quite recommend you to look up a psychologist, psychiatrist, psychotherapist.
Good luck to you

My mum once kicked me because I stood on the couch. What a bitch.

Not normal.

Oh my Lord! I am so sorry those things happened to you. My sister's ex boyfriend's mother rubbed his nose in his feces when he was a toddler.

Yes (like my mom)!
☆ . ☆