Why did I write a novel?

People often ask me what inspired me to write a novel, and I find myself quite unprepared for the answer. I am fortunate not to have had major tragedies in my life, which have been known to fuel the ink of a large chunk of literature that exists today. This is the simple answer that has come to mind:
There are perhaps four ingredients one requires to create a novel. The first two I believe I always had- empathy and imagination. The other two took several years to find, which is why I could not have written a novel ten years ago: maturity and time.