I wanted to add a little comment onto my last pondering about following God's leading.
I was thinking about how some people seem to struggle (sad, angry, frustrated, etc.) when things do not go as they had planned or when God shuts a door and says 'no' to what you are planning.
I am sure I have been there before, but I (we) usually rejoice now when God shuts a door. Why? Because that means He is leading us, and that is our first and foremost desire -- to follow Him and His leading of our lives.
And, there lies the difference. Our heart's desire.
If you struggle when your plans don't work out, then you have formed an emotional attachment to them.
Only set your emotions (heart, mind, soul) on Jesus Himself. Not even on good ideas or other good things. Just Him. There are many good things that He does not call you to, even if it seems like a perfect fit.
Then, when He says 'no' to something, you will not be phased one bit. In fact you will be glad for any direction. Because you were not emotionally attached to some desire or plan of yours, but on Christ alone and following His lead.