It’s all the TIE Fighter’s fault.
There I was, trying to do a quick sketch, when the pen had to slip and make this weird squiggle inside what was supposed to be the outline of the cockpit. Never one to give up easily, I proceeded to work that unexpected bit of ink into what became the cockpit window.
However, the original circle I had drawn for the entire cockpit was now just the window, so along comes a bigger circle. A circle which is, of course, a bit out of proportion with the wing I had already drawn.
And thus a just as strangely-proportioned X-Wing is born, to cleverly trick people into the idea that I had planned this all along.
A trick which I have apparently just ruined.