Juan is good person most of the times but could also be sarcastic, stubborn, and a complete asshole to people he doesn't lile. lilehe could also be kind and funny when he feels like it.
He suffers from dark moods but is also inclined to deal with it by being even more busy and distracted. They may be adamant to friends that they're fine but slip into morbid terrain in private. Remembers every insult ever said to him from the age of 5. Drowns away his problems in milk and music.
Juan: hay I have a question abou-
random guy: no-one cares Juaaaaaan!!