You'll be in a constant state of self-reflection

When living abroad, figuring out your identity and how you fit in (or don't) is an all-consuming part of life, especially in an extremely homogeneous society like China's. Han Chinese make up 95 percent of the population, so (assuming you're not Han) you'll be perpetually reminded of the fact that you're a waiguoren (outsider). Even if you are indeed a foreign-born Han Chinese, you may still receive a constant bombardment of statements about your other-ness. An American-born Chinese friend of mine was frequently told, "You're not realllly American," or "You're not realllly Chinese", when actually he is both. There's a litany of differences, both minute and great, that you'll notice when working abroad. Table manners, spatial barriers, volume, physical contact, hair color, what "politeness" really entails, phone usage, the capacity of technology, the role of gender in society, clothing, and so on. This list is non-exhaustive, but when you're confronted with issues as trivial or pressing as these every day, you're bound to change. If you're hoping to teach English abroad and answer the age-old "Who am I" question, you'll certainly have plenty to go on.