[trod1234]

I was lucky enough to have several teachers that were able to undo a lot of the damage bad math teachers imposed on me (on a lag) and continue on from Calculus to the foundations of mathematical systems (Abstract Algebra).

I've also used that knowledge quite a lot since, both in reasoning about problems and its also been beneficial in the confidence of accuracy in the methods of problem solving.

Bad malicious teachers nearly tortured math out of me. Without a substitute teacher who retired due to malicious politicking of his pears; but who had a phd in Mathematics Education, and was able to narrow in on exactly what I was taught that was incorrect (3 classes prior to the one being taken); and the patience and technique he used to destructively correct the false teachings while alleviating the operant conditioned anxiety; I wouldn't be where I am today.

There's quite a lot of malevolence in the world based in blindness, fortunately there are also some good souls out there helping elevate others.