Hi, here are a few previous threads that can get you started, until someone can address the question how "why it stuck"

• Were the right-to-left seating arrangements at the Estates-General of 1789 by social rank or by ideology?

• Why does 'Liberal' have a different meaning in the US than in Europe?

• Why is Liberalism considered right wing, when it was the Liberals who sat on the left in the French Revolution?

On a related note, I have heard that the modern left-right divide in politics stems from differing interpretations of the work of GWF Hegel (with the "Young Hegelians" forming the modern left). Is there any truth to that?

This might not be precisely what you want, but on /r/asksocialscience, I wrote a long post about alternatives to thinking of left-right as the normal axis of politics.