My previous question revealed that the context for 本人 should be much more formal than I thought. Below is an example from last year’s 閱讀課： Is this guy trying to impress his potential landlord with his mastery of formal language and ongoing PhD? In my native languages, informal language would be OK! I asked my teacher the same question last year and her opinion was, you didn’t need a formal context, as long as it was written. I suppose some deep mystery is hiding here, not easy to grasp for 老外. Perhaps I need to understand what “formal” means to Chinese.
Next, an example from the Internet, taken from here and a google plus profile:
Is this due to regional differences? Can Taiwanese natives please comment on whether this is natural to them?
A further example from the internet, found here, seems to start somewhat formally and then finish totally colloquially with 求計算機大神導致：