I tried Bathurst yesterday, which isn't a track I've ever raced. Setting aside the horrendous rest of the track, I must have taken that first corner about 50 times yesterday. Brake, turn, accelerate. I watched his replay, he's doing exactly what I'm trying to do. Every time I'm at least 0.05 down on him by T2. I didn't improve after 50 tries, and when I'm 0.1 down by T2 rather than 0.05 down, I have no idea what exactly it was that made me 0.05 slower than my best attempts, I'm unable to discern any difference in what I did. So as I can't tell what I'm doing that is better or worse, I can't learn to repeat the right things and avoid the wrong things, as I'm just not able to discern differences at that level, it's the limit of my ability.
You see the same thing in swimming, for example. I once saw Ryan Lochte say in an interview that he felt anyone could win an Olympic gold medal at swimming if they were willing to do the training required. It's the same thing, a static unchanging challenge that you can take on over weeks, months, years. But almost the entire human population lacks the ability to discern the tiny technique differences needed to swim at that standard, and will never be that good, even if they train for 4 hours a day every day for the next 10 years.