Story where a traumatised soldier in a hospital vanishes. ‘Experts’ don't understand that poets did this all the time and not a poet can be found anywhere. The story was in English. Perhaps it was by Asimov.
This is Alfred Bester's Disappearing Act.
He waited for them to find a poet, not understanding the endless delay, the fruitless search, not understanding why Bradley Scrim laughed and laughed and laughed at this final, fatal disappearance.