So, I learned basic html a couple of years ago, but forgot most of it. Is there any reason why I should try to learn the basics again?
If your looking for a hobby such as web development I would suggest you would. Plus brush up/learn CSS as HTML is nothing without it.
HTML is all a language that is used within all design and development projects. It is the framework of a website and helps set everything up. If you plan to create websites or get into web development for other things, then I would suggest you learn and master HTML, CSS, and JS.