Well,. there are lots of speculations that have arisen why it happened but from a reliable source, I got that Ronaldo wasn't interested in Real Madrid again because the Board were not appreciating his effort. Whenever he didn't perform too well in a game, they begin to threaten him with the issue of selling him off and looking for a suitable replacement for him. Also, when he had the tax problem, none of the Board members assisted him to solve the issue so he had to combine his football with catering for himself and other things too so this enraged him and triggered his opt for transfer.