Jean-do

I see a lot of people asking "why was he treating his ex wife badly" and similiar questions.

One of the things that I think us, the viewers, should notice is how Jean-do is NOT exactly a good guy. He left his 3 children and their mother (and when he visits them, to them he appears like a film star in his fancy cars and clothes) to carry on with his affairs, feeling and living like a bigshot.
In many ways he's very immature, and VERY child-like (he only really takes care of his father, while he never brings his children to visit their grandfather; his EX WIFE (whom he left) does that!).

But all that is a part of what makes this film interesting. When he ended up in a hospital, no longer could he live his life like this adventure, with no responsibility. So all he has left are his memories (his re-examining of his past deeds) and his imagination (again, the child in him).