The Science of Developing Mental Toughness in Your Health, Work, and Life (and How That Will Make You a Better Artist), is an insight on the mental trades you need to kick ass as an artist and do great in life, no matter background, grades or heritage,
I have to say that only with perseverance and grit I've accomplished some major goals in life, despite of having to work full time/part time while being punched left and right with all the unexpected things only life can deliver (without mentioning politics at every level, which its an article of its own).
It's a lonely road to the top though, a road filled with tons traps, detours and sad moments,
However, when you reach your destination you'll realize that everything worked out for the better and any battle scar you have gotten is part of your reward and your character.
So read THIS great article from James Clear and build some mental muscle to become tough enough to break through any vermin ridden jungle with both arms swinging in victory!