Take everything with a grain of salt. And yes, that includes this blog, too. If something I'm saying does not apply to you, that's perfectly fine! Just take what you need and leave the rest.
I've come to learn that people always tell you what works for THEM, and more often than not, they make it sound like hard and fast rules. Guess who's going to tell you that you absolutely HAVE to keep a sketchbook? - Those artists that are naturally very good at keeping sketchbooks.