Why were you fed up of China?
Many reasons. The first time I was there as a tourist was daunting, having zero language at that point, but I enjoyed travelling around for a bit. When I went to actually live there, it was to attend a university. They treated us basically like kids again (I was 21 at this point, so having to write essays of apology for missing a class and the campus being locked down at 11pm, with the electricity turned off in the dorms at midnight, was a bit annoying).
Moved out of the dorms, got my own flat, and just found everyone so cold and unfriendly. None of the neighbours would talk to us, they'd just call the police to my flat if they had an issue with something, and we were told on our first day to just not get involved with any domestic issues I saw. Getting anyone to open up and talk was next to impossible, and it became frustrating knowing what was happening around me regarding censorship and oppression, and not being able to talk about it, let alone do anything. One of my friends was living with a host family, whose father got a visit from a government official over something my friend posted on the blog he was keeping, as the father was one of few people to actually talk about his dislike of the political system.
I accept that this is different in top-tier cities, Beijing, Shanghai, Guangzhou etc, and I've always said that if I moved back to China, I'd have to live in one of those, as there is actually a sense of a youth movement creating art and music using influences from the outside world. But still, I didn't like the pollution, the spitting, how generally grey and dirty everything was, being stared at constantly or my landlord always trying to cheat me - but mostly the culture of silence and keeping your head down. That, and the government bulldozed my favourite bar to build a road through it. Pfft.
That's not to write China off completely, I had a lot of fun in Sichuan/Inner Mongolia/Beijing at various times, but I'm so much happier in Taiwan, where freedom of the press/speech is valued and everything just works. It works differently to home, but it does at least work, and everyone I've met so far has been incredibly welcoming - I've not had a journey yet where the person next to me didn't try to start a conversation (usually to make sure I was having a good time in their country).
...Wow, that was longer than I'd expected.