Chinese English names

In China, many people have a second, English, name. This name is often given by a their school teacher or by themselves. It is interesting and sometimes funny to see which names are chosen. In my company there are Chinese Christians who have given themselves names of important biblical figures, and people who have chosen a name that sounds similar to their family name. Also, some colleagues took the opportunity to call themselves after a famous. And of course, many just chose a name they liked for no particular reason. Actually, I always felt a bit awkward about these English names; the only real name you have is the one given by your parents to my opinion. But besides that, so far so good, no problem.
It becomes complicated, however, if people suddenly change their English name. Really, this happens! This week, a colleague of mine left the company, and later informed me that she had changed her English name, because the one she used in our company was only chosen out of convenience, since her previous name was too common here. Now, she changed her name back again.
I hope, this doesn't happen too often. It would make talking about people really difficult: you never know who you are talking about.