Everyone starts their design career in the same place. We might have an inclination of what good design is, but we suck at the execution. But we go to school or teach ourselves the software, the rules, the techniques and we improve dramatically. If you don't believe me, open up your first Photoshop project (if you still have it) and just look at the Frankenstein you created. Remember back to when you got excited about the dumb little features you learned in Photoshop and fully abused them (think Blending Modes, every single Layer Style, Filters, etc.).
Most of us learn about critiques in design school, where a design is judged by how it adhers to design principals and the person giving the critiques’ personal opinion. In the real world a design is judged on how it stacks up against the competition. When you are designing for keeps and not a learning experience, the rules change.