Edit:
To make what I'm saying a bit more clear: There's a ton of people in these threads assuming that not everybody is born with math skills (or variants of that attitude). That is exactly what these teachers thought and how different my life would've been had I agreed.
It sounds like that was implemented very poorly in your case. You yourself said "I was immediately bored in our lower maths class". I don't see how the solution to this is to make everyone take the lower math class. Certainly there is some middle ground between the California plan and what you experienced.
It’s hard to see that as undermining tracking as a concept, since the problem is actually the absence of oversight and termination of bad teachers. No one teacher should have the power to doom a student, but a school needs to be able to recognize and cultivate talent.
It sounds like the implementation of levels was especially bad in the OP's case though, so I agree it isn't really a good anecdote to argue against leveling entirely like California is doing. It's throwing out the baby with the bathwater.
I'm trying to figure out how this relates. It sounds like you had a bad experience with tracking, and there is a fundamental issue with tracking where some amount of people will have bad experiences, but ultimately you were able to achieve your potential anyway, so why make the experience bad with tracking if people will eventually get to the right level over time - is that a fair interpretation of your comment?