He had terrible fashion sense, and a habit of making people angry
Although Michelangelo was never married and had no children, it is said that he had relationships with both men and women. The remarkable thing about Michelangelo was that, despite becoming wealthy, he lived close to poverty and hardly ever took a bath or even changed his clothes. It is reported that when he died, his garments had to be cut and peeled off of him because they were so filthy and stuck to his body. The artist led a secluded existence in his later years, only having contact with others when required to do so by his work.
Many of the traditional characteristics of the artist were exhibited by Michelangelo. He was hard on both his efforts and himself. I am not a painter, he famously said in one of his many letters regarding his work on the Sistine Chapel.
He was notorious for his critical, unpredictable moods and frequently unsatisfied. In fact, Pietro Torrigiano, one of his classmates, was so enraged at Michelangelo for his talent or, more likely, for his sharp mouth that he hit him in the nose, permanently twisting it.