''Why are they so happy after repeating their semester and losing their stipend?''
This question?! You're asking this question in case of Jagya? 😆😲
You know he's forever happy. He was very happy gambling in full concentration after stealing his mother's jewellery, got caught and beaten up, but happy again to read dirty magazines and gape at semi-nude women, got caught and scolded, again happy to run away from home with Sundar!
He's always happy, no matter what conditions are. He's always happy. Not caring about past, not bothering about people or laws, just doing what you want to do, that's what gives happiness.
And Gauri has picked up such skills from him only. Just that Anandi's mention makes her unlearn all skills and gives her frustration and painful flashbacks!
Who knows? If J is sent to jail (for any reason, not just illegal marriage) you might see him playing antakshri with fellow inmates or eyeing female inmates or constables.
Jagya knows how to be happy in any condition until someone else spoils his fun by reminding him of family or past!