I'm a ________ not a _________.
One of my favorite things to say when confronted to justify giving something a particular name, whether it be code, a product, etc. is: "Sorry, I'm a programmer, not a poet." Similarly, I can hide behind "I'm a programmer, not a designer."
Poppycock. These are just excuses to cover inexperience, ineptitude, or just flat out hide embarrassment. No more. Part of self-improvement is stretching one's self and exploring different trades and expounding on the ones already learned. I'm sick of not having a seat at the table because "I'm not a ___."