Michelangelo di Lodovico Buonarroti Simoni, or the artist known as Michelangelo (there’s no record of him answering to “Mike”), is perhaps the most celebrated Renaissance artist of all time. Among his many works, the ceiling of the Sistine Chapel in Rome remains his grandest accomplishment.

And he was a nervous wreck about it.

Michelangelo had come into renown as a sculptor and considered painting the 12,000 square feet of the ceiling beyond his capabilities. He was wrong, of course, but the artistic anxiety caused him considerable distress. He even made sure the first portion of the ceiling, The Flood, was tucked away and largely out of sight in case he messed it up. He famously worked 65 feet in the air on custom scaffolding, and after four years of effort from 1508 to 1512, the physical toil of craning his neck upward was apparent. (He did not, as is sometimes thought, paint while lying down.)

To relieve some of the emotional tension, Michelangelo took to poetry. He wrote an Italian sonnet in 1509 expressing his frustrations over tackling such a formidable project, with years of toil ahead of him. The work, sent to friend Giovanni da Pistoia, reads:

I've already grown a goiter from this torture,
hunched up here like a cat in Lombardy
(or anywhere else where the stagnant water's poison).
My stomach's squashed under my chin, my beard's
pointing at heaven, my brain's crushed in a casket,
my breast twists like a harpy's. My brush,
above me all the time, dribbles paint
so my face makes a fine floor for droppings!

My haunches are grinding into my guts,
my poor ass strains to work as a counterweight,
every gesture I make is blind and aimless.
My skin hangs loose below me, my spine's
all knotted from folding over itself.
I'm bent taut as a Syrian bow.

Because I'm stuck like this, my thoughts
are crazy, perfidious tripe:
anyone shoots badly through a crooked blowpipe.

My painting is dead.
Defend it for me, Giovanni, protect my honor.
I am not in the right place—I am not a painter.

Fortunately, he persevered, and his work in the Sistine Chapel has been a source of inspiration and awe for 500 years and counting—an artistic feat that may never be duplicated, and one well worth the sacrifice of his poor ass.

[h/t Slate]