You will not be the only writer in the agent's line-up. As you wait for your first sale, continue to hone your craft, and work contacts and opportunities on your own. Numerous books exist to help you get the ball rolling. Throughout your career you are likely to find exceptions to everything in this article. Not a problem.
Exceptions exist for every rule.
In fact, I encourage you to print this article and scrutinize it. After you've pondered these questions a bit, defiantly scrunch the paper into the smallest ball you can manage and fling it across the room. After all, you're not a rodent and I'm not playing a flute. Find what it is you want to do, then do it. If writing really is your passion, then write.