"When I have a full schedule like that, I don't see myself sitting there for a couple of months, doing the research, going through a painful process, it's just not my thing anymore"

Ang Lee is revealing his reluctance to handle a job that needs a lot of time and effort. He is suggesting that he is no longer thinking about dedicating a substantial amount of time to a task, particularly one that needs a great deal of research and a long, drawn-out procedure. He is recommending that he chooses to take on tasks that are more simple and need less time and effort. This could be due to the fact that he is more skilled now and has a better understanding of what he wishes to do and how to do it. He is also most likely attempting to save time and energy so he can focus on other jobs. Ultimately, Ang Lee is expressing his choice for projects that need less effort and time, which he is no longer interested in devoting a significant amount of time to a single project.