What's the garment that made you feel fully, unmistakably yourself?

Hi everyone, I am a sculptural sustainable fashion designer, curious about your “once in a lifetime” garments.

Can you think of a garment you wore on a special occasion that enabled you to feel yourself and fully confident? What was it and why was it special; was it the story behind it, how it fit, its ethical values, its colors, the designer, etc.

I see fashion as a fundamental form of self-expression, and wish to understand what people truly value, instead of assuming unknowingly. Thank you to everyone who takes their time to answer!