'Hound Dog' took like twelve minutes. That's not a complicated piece of work. But the rhyme scheme was difficult. Also the metric structure of the music was not easy. 'Kansas City' was maybe eight minutes, if that. Writing the early blues was spontaneous. You can hear the energy in the work.
The boarding-school experience in Paris was very hard, I didn't put up with it very well. I was sick all the time, or in any case frail, on the edge of a nervous breakdown.