Verbatim Theater

Verbatim Theater - embodying another person and telling their story as them.

I opened my mouth, and my mind went blank. I mean, really, blank. I couldn't remember a thing. 
We were standing opposite each other, and she was telling a story. Something about food. I was watching her. Her hand movements, the way she gestured with her arms emphatically in certain places, the tone of her voice, and at which moments she got excited. She used her hands a lot, her head was never quite straight. "Repeat her story." I turned around, my mind went blank. My cheeks flushed. I was embarrassed. The others had all managed this without a hitch. I couldn't remember a thing. The others stared, incredulous. Perhaps I'd focused too much on her movements and not enough on her words?We did it again - for me. I was flustered, embarrassed. I tried to focus on her story - she talked about foods I'd never heard of. I could do this. "Repeat her story."I tried again. I faltered. My mind went blank. I wanted to sink into the floor and disappear. I don't know why I couldn't do it. Eventually they gave up on me, and it was my turn to tell her a story, but I was so upset I couldn't even think of anything proper to say. It was patchy and dumb - something about being selfish about popcorn. Stupid. 
I love our group - they didn't make fun of me, or laugh at me. They just kept going, told me it was ok. I couldn't tell anyone's story, and barely managed to stumble through my own. Yet these are not strangers - the exercise ought be easy - we know each other. He rubs the back of his neck when he's feeling awkward, she talks really quickly and with a lot of emotion, and she uses large gestures to accompany her words. 
I don't know why I can't do this.