Earlier quoted context omitted.
To be fair to your mother, this particular advice and view was rampant when I grew up in the 80s/90s. My experience was that this is quite backwards. Physical altercations at school didn't hurt that much, but the name calling, social shunning and constant verbal put down was very painful and has affected my whole life.
“Sticks and stones may break my bones but words will hurt for life” is how I used to say it. Never say anything that couldn’t stand as the last thing you say to someone. You’re words matter more than you realize.
Being beat to that extent can cause both physical and emotional pain for life.