Your math skills are probably better than you think and your memory is clouded by emotion that recalls the stress of the time. So you remember that you were le

Your math skills are probably better than you think and your memory is clouded by emotion that recalls the stress of the time. So you remember that you were less competent at it then you actually were. This is very common but I've forgotten the psychological term for it. Think of it this way, you really showed that teacher that he/she was wrong. You are a success and a software engineer. Adults who say the things said to you are typically bitter at their own life outcome. Aka it is more about them then it is about you. As to your performance at age 16, remember also that your brain was still developing. The prefrontal cortex doesn't fully develop until your 26. And I suspect it still develops after that. We know that alcoholics stunt their developmental age essentially at the age they start drinking because they quickly mature after getting sober. Stress has a similar effect. Anyway if GCSE maths is really what you want to learn again, then you can find the topics covered online and study those. There are plenty of resources from textbooks to youtube etc... it is a golden age to self study. If you can't self study you can probably find a tutor. The big thing is to learn how to learn and to do that you learn how to teach what you're learning. For "work" though I would say the best class you can take is a class in statistics. And if you find the basic class in statistics too hard then go back a bit to a class before that (probably calculus). But I would just pick up the calculus you need for the stats. Really all you need is an understanding of a derivative and an integral. Or maybe start with the undergrad business school version of statistics or statistics for engineers etc... If you learn statistics you will be in the top 1% of software engineers. After calculus and stats if you are interested in deep learning you might want to take linear algebra for engineers. Understanding what a matrix is and some basic operations on it can be useful. But that opens up a big can of works though and it is quite a competitive space now because there are many engineers who work as programmers and learnt all of this stuff in school now have an outlet! It is also an exciting time. One last thing would be to ask your colleagues for help understanding the metrics. Pick someone who is friendly and nice and they may be delighted to explain it to you.