[sigmoid10]

Assembly would be a good start. But to really make use of that you need to learn the internal intricacies of processor architectures and operating systems. If you want to be employable, there's just a gigantic amount of seemingly boring details to learn before you can even start to build something interesting. With high level languages you can jump into the job market almost immediately, so the cost of entry vs. potential reward is better for most people. If you don't have fun when spending years of your life banging your head while digging down incredibly complex rabbit holes, it's probably not worth it.