Of course you don’t have to. But seriously, the barrier to entry is actually way lower than it seems. Especially if you’re working alone a project. You can just start with one feature for a project, and get used to it that way. That’s how I started with preprocessors (with Less–I’ve since repented :). I found that it felt really natural, and was easy to move on from there. I still don’t use it to it’s full potential all of the time, but it’s really easy to cherry-pick the parts that are going to help you most with any given project.