After studying philosophy and theology for a decent portion of the last few years, I've found that there are several so-called "classic" questions which humans in general (and Christians in particular) tend to wrestle with. Here are some examples:
-To what extent do humans have free will?
-What happens to us after we die?
-Why do bad things happen to good people?
-How do we know whether we really know something?
-Is the phyisical reality which we experience with our senses the sum total of reality?
-To what extent, if any, is there absolute truth?
I would like to provide my own contribution to this list:
When in the library, at what point do you tell someone that, though they are wearing their headphones, they are not, as it turns out, plugged into their computer, and that their Youtube video is broadcasting loudly to the patrons of said library?
My answer to that question: when you can't take it anymore.
If you'll excuse me for a moment, I need to take care of something...