I really think that free will is just an illusion.
When we are born, our minds are nothing but instinct. As we learn, we gain mental pathways through which connections are made. For instance, we first begin to make connections like bottle::milk and ::ball::enjoyment.
We begin to learn language, and that works in the same way: we learn how to structure language, we learn how things are funny, etc.
Socialization follows the same pattern. We learn to converse well, we learn that some things aren't appropriate.
Sometimes we'll see a propane tank and it will trigger us to wonder why it is in a different place than where we last left it.
Occasionally, we will arrive at home and there will be a window open that isn't supposed to be open, and that will cause us to always check things like that before leaving.
This goes hand-in-hand with Chaos Theory: nothing is really random. If a drop of rain falls, it's not out of randomness, it's because of the different concentrations of gas, the speed and direction of wind at all the different elevations, what molecules it happened to hit on the way down, and many other variables.
Thought works the same way: if you have a conversation, just watch its progression: you'll see that there was always some train of word association, observations, or subject associations that change and progress the subject.
Every event in our life shapes our being in some way. We only really repeat what we are taught: new ideas emerge as a result of using different thought pathways on different ideas.
The result of this is that we don't actually have "free will". Free will would be the ability to think in a way completely different than anyone ever has, to act in a completely unnpredictable way (You may try to act unpedictably, but what you consider to be unpredictable is a result of what you consider to be predictable)
Discuss.