Great photo, isn't it? That Knowledge is Key looms large in almost every facet of our lives isn't news. But it most certainly is something to keep in mind in whatever we are striving to deal with.
For writers, it's especially helpful. You may be a wonderful writer but if you don't educate yourself about the literary world, the marketing process, and publicizing your work, you may find little success. What a shame to allow good writing to languish in your files instead of finding a place where your words can reach the eyes and hearts of readers.
For beginning writers, I can't stress enough the importance of reading everything they can find about writing. That includes the mechanics, which can sometimes be pretty boring, all the way to the submission process, building a platform, and keeping your writing knowledge as up to date as possible.
One by one...
Mechanics Grammar, word usage, point of view, plotting, themes, showing more than telling--all these things show in your writing. It's vital that you master them. Those who don't find more rejections than acceptances. it's as simple as that. Even if what you have to say is great, poor mechanics in your writing will sink it faster than an overloaded ferry.
Submission Process It is to your advantage to study--note the word study guidelines and then follow them carefully. When you're ready to submit, go back and do a checklist with the guidelines. Some publications have very specific rules, while others are a bit looser, and some give you no direction whatsoever. Learn all you can about the publication to which you are sending your work.
Building a Platform You are your own agent. You are the one who has to get your work and your name before the reading public. There are so many parts involved here that I'd suggest googling building a writer's platform and read some of the articles.
Keeping Your Writing Knowledge Up To Date You can read copious amounts about the writing world in 1995 and then move on. But if you do that, you won't keep up with the constantly changing literary world. The mechanics may remain relatively the same but other things will not. Think about ebooks. In 1995, they were unheard of. It's to your benefit to stay abreast of the newest innovations in the writing world.
One last thought. We all concede that Knowledge is Key but I'd add a little more to that. Keep in mind that New Knowledge is Key Everyday. It's an ongoing, never-ending process.