Based on the hadith, in Jannah, you will have everlasting happiness and you will get anything you want. But the real question is, what happens if two people have contradictory desires? For example, two people see a tree with green leaves. The first guy wishes the green leaves turn yellow. But the second guy wishes that the leaves stay green. What happens then?
And also, will we have our haram worldly desires in Jannah? For example, let's say I was sadistic and I have this intense desire to hurt people for my own pleasure. But just for the sake of Allah, I refrain from hurting people. Will I be able to fulfill my sadistic desires in Jannah?
I always had my own theory of what Jannah might be like. According to my theory, everyone in Jannah will be living in their own "bubble" or in other words, their own "dimension". So if you see someone you know, then that's not really the actual person. That's just a "copy" of that person living in your dimension. So if you kill that person, he/she is not really dead. It just means that the person got wiped out of your dimension. The real person however, is just living in their own dimension. But this is just a theory I came up with.