I like it a lot. If your teacher dislikes the Mythology part then they are silly, I like that you came up with this from what they gave you as an outline, great job.

I think you worked the brown bag element very smoothly into your story; the fact that it was used to contain the pride of humanity was brilliant. Overall, an interesting take on Pandora. Best of Luck.

I love how you ended with Pandora's comment about having hope.

I think it's well-written and humorous. Pride in a bag. Who's ever heard of such a thing?

What you have said about pride is the truth: it is our greatest strength, and our greatest weakness. That observation should at least get you a few points, in my opinion.