Do you find yourself pushing CSS to its limits to avoid wiring together another jQuery plugin to create parts of the web-app you desire?
Are you sick of learning proprietery mechanisms and idioms of frameworks, that you can't use in the real world anyway?
If you knew how to quickly create re-usable components from scratch, you could stop worrying how you are going to assemble your UI every time a new project pops up.
You would no longer wonder what part of the DOM API you need to learn, to produce first-class dynamic content. You could get started building your highly customized components today!