The will of God. In many evangelical circles it is seen as some quasi-gnostic secret knowledge that only the faithful discover. What does God want me to do for a living? Who should I marry? Where should I go to college? These sort of questions are transformed into opportunities to either make the "holy" decision or forever fall out of what could have been God's wonderful plan for your life.
In my experience this line of thinking is disastrous.
Thankfully Kevin DeYoung has written a fantastic little book that addresses this often misunderstood subject. The following exert from Just Do Something: The Liberating Approach to Finding God's Will captures his overall argument succinctly.
"Wisdom is what we need to live a godly life. God does not tell us the future, nor does He expect us to figure it out. When we don't know which way to turn and are faced with tough decisions in life, God doesn't expect us to grope in the dark for some hidden will of direction. He expects us to trust Him and to be wise."
In other words, as long as your primary motivation is to glorify God... just do it! God can use you in Cairo or Chapel Hill, so stop stressing out over the small stuff and take some chances.