to be fair... credit where credit is due... that's past life, to be reincarnated knowing what character you're getting and what fucked up family you're getting and not just killin' yourself in the first day of you being aware probably takes a bit of mental fortitude. but i get you tho, i also don't see her as the strongest mind, maybe that's his personal opinion and she's just immune to mental attacks? or something similar? i don't know QAQ

I don't understand how we went from the weird dude saying she has "the strongest mind" to this flashback where it shows anything but a strong mind. I need them to point out where this "strongest mind" they were referring to is because I don't see it. And that's not meant to be a diss at the MC.
Most children that do extra curriculars like sports and music at a serious, competitive level were pushed in that direction by their parents. No 6, 7, 8 year old is going to tell you "I want to pursue X" if it wasn't a path their parents had already put in front of them. In the competitive world, for whatever activity, some people do have crash outs after they realize they are only doing the activity because of their parent(s) and that they never grew to enjoy it. It's very common. Doing something out of being pressured creates a weak will. And weak-willed people are usually weeded out way before they even get to compete at the top level because they ultimately end up making mistakes or don't have the fortitude to be calm/consistent during competitions (this is what happened to MC). You have to be hella strong minded to be a professional athlete, musician, etc, and MC didn't get to develop that. That's fine and all, and she doesn't need to be a top violinist to be deserving of her mother's love. But nothing in this story has shown that the MC has the "strongest mind". I don't understand if either the author doesn't know what having a strong mind means, or if it was just a translation error.