These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Awesome Ego: When he was still able to perform, Beethoven would pointedly stop playing if he heard any of the audience members whispering. He broke a chair over the head of one of his patrons. And yet he wasn't locked up; his behaviour was taken to be evidence of his genius, and indeed his disdain for authority and social rank was so pronounced that an Archduke decreed that etiquette laws did not apply to Beethoven. He wasn't the first composer to have an Awesome Ego, just the most famous.note The first recorded case of Awesome Ego in a composer was the 15th century French composer Josquin des Prez, one of whose prospective employers was warned "he composes when he wants to, not when he is wanted" but who became so famous that dozens of works have been attributed to him that he probably didn't write; musicologists are still sorting out the mess.
Crowning Moment of Heartwarming: At the end of the first performance of the ninth symphony, which Beethoven directed himself despite being completely deaf, the audience gave him five standing ovations - and they did it by waving hats and handkerchiefs in the air so he could see the applause he couldn't hear.
Sampled Up: Henry van Dyke's hymn "Joyful Joyful We Adore Thee" is set to Ode to Joy.
Vindicated by History: The first performance of the Ninth reportedly was a bit of a failure, and after opening night it did poorly. Possibly partly because Beethoven insisted on directing it himself despite being completely deaf - to the point where he was still conducting after the orchestra finished playing.
The premiere of the Fifth Symphony was in a concert that lasted four hours on a cold, December night and the audience was tired. Needless to say, it was not very well accepted in its first performance. It took a review by E. T. A. Hoffmann to bring its genius to light.