Literally, why are we here? What was the cause of our existence? I'm not asking "what is the meaning of life?" I'm asking "what is the mechanism which causes our Universe to exist?" This is the goal of the LHC: to find the reason our Universe is ordered the way it is. Many talk about this as "The Hunt for the Higgs Boson". I learned today (via a special guest speaker in my classroom) the only particles needed to build our Universe are two types of quarks, electron neutrinos, and electrons. Wow. Our physics research (worldwide) wants to know "why do these particles exist?" "What causes our these particles to exist?" "What is it that tells those particles to form?"
Talk about some big questions! Its a really difficult issue to wrap your brain around. In fact, I'll admit, I can't do it. I'm not sure I could ever be a part of the collaboration(s) which are trying to study this. Its some big picture thinking, and I'm not great at that. I try, in class, to impress on my students the level of thinking at which top scientists work. I admit freely to them that I am not capable of this level of thinking. I suspect that every now and then I will run across a student who is and I hope I can inspire them to choose an area of physics which suits their level of thinking.
I realize you came here to get an answer to this post, but I have only raised more questions. That is part of my job as a teacher, not to answer questions, but to encourage students to ask "the right questions" (see critical thinking). So, have I done my job? Do you have more questions now than you did a minute ago? Go ask the right questions!