As a kid, Zukos mum encouraged his love for the arts. Zuko loved wrighting and playing music. He would tell her all about how one day one of his songs will be played on stage.
When she disappeared anything that wasn’t war was considered week and somthing to be ashamed of. As a loyal son all his music stuff was packed away . And he stopped going to the theatre .
It was shameful hobby for a prince
When he was banished he certainly had a lot of time to himself away from his fathers disapproving eye And in the encouraging eye of his uncle. 
He started wrighting again and if he joined music night on the ship . No one commented .
Over three years he filled many notebooks of music . Some of it was just angry venting . But some of it was good .
In ba seng se he would spend his days off watching the shows by the amateur dramatic groups . If asked he would complain it was a waist of time but he would always watch to the end eyes glued to the stage.
if his vigilante persona was a character from his Favorite play. No it wasn’t
When he joined the gang he didn’t realy have time for hobby’s but katara found his notebook when she was snooping through his stuff to “ find proof that he’s still evil”. Zuko found this horribly embarrassing but kataras couldn’t help but find it oddly endearing
As he started to bond with the group he even began to share his interests.
Him and sukka bonded over there love of poetry .
Toph thought the note book itself was boring. But she bullied him into playing some music on an instrument she found and she had to admit that he was really good.
they all found it amusing to listen to the normaly quiet boy rant about everything wrong with the ember Islend players .
At his coronation Zuko wasn’t well enugh to do any of the traditional coronation festivity’s , he could barely stand . So the fire nation decided to put on a show in his honner to celibrate the end of the war . So all he had to do was sit still and watch
As ang called it “the ember Islend players the corect way “
Though sukka would deny involvement . One of the performances played on stage sound a lot like one of zukos songs.
And if Zuko got all choked up grinning like a idiot . No he didn’t .