My mom also knits while watching TV, and she is super fast. I think one secret ingredient is that she doesn't care about making mistakes. Tinier mistakes she just ignores (even if they are visible in the end [I don't like that, so that's something I try to avoid, which adds pressure and slows me down]) and she doesn't mind backtracking and re-doing several rows if she really fucks up.
My grandma seemingly didn’t ignore or tolerate mistakes. That’s why she ended up stopping. People tried to get her to crochet or knit toward the end of her life and if she made a mistake, she’d start ripping it all apart. When the mistakes became too frequent, that was it. Maybe that’s where I get it from, lol.