Why did Felix Mendelssohn consider his String Octet one of his favorite works?

Felix Mendelssohn regarded his String Octet in E-flat Major, Op. 20 as his favorite among all his compositions primarily because of the immense joy he experienced while creating it. He explicitly stated, "I had a most wonderful time in the writing of it!"1

Beyond his personal enjoyment during the creative process, the work is celebrated for its technical mastery, melodic fluidity, and a delicate balance between its eight parts. Written when the composer was only 16 years old, the octet displays an unprecedented lightness of touch and rhythmic originality that Mendelssohn would later refine in other famous works, such as his incidental music for A Midsummer Night’s Dream.12