@Shams
So essentially - what we think is free will - is actually fate, determined by a billion minor (and major) variables both within our minds, memory, driven by our external senses - and to a certain extent "randomness".
I think your definition implies a meaningless existence rather than fate. If everything is indeed determined by 'randomness', then you didn't have a choice to come up with and write that point, then your point is meaningless and might as well have never been written. I believe that Human beings are both physical and spiritual creatures, not simply a mess of chemicals comprising an advanced machine. Your definition fits animals, who react in all situations to their basic instincts, but I believe humans do not fit this definition.
To assume fate, most people assume there is a larger force that sets that fate. I believe that fate and free will are intermixed. If there is a god that sets fate for certain purposes, He would have to live outside of time. Many people will say this is impossible by using reasoning from their own limited perspective on the universe (I can't rationalize a world without time, therefore it cannot exist). The problem with this is, we can't fully understand something we have no way of rationalizing due to limited experience. For example, the light spectrum expands far beyond what we can see with our eyes, down to infrared and up to ultraviolet, there are some animals who can see in these light spectrums and therefore see colors that we cannot. Now try to imagine a color you've never seen before... It's impossible to do, because you have no experience to back that up, but that doesn't mean there aren't more colors than what our eyes can see. The same principle applies when we as time-limited beings try to discuss and rationalize a God that is not limited by time.
Now back to fate. I personally believe that fate and free will coexist together. We see life as a parade watched through a peephole in a fence; only able to see what is right in front of us. God, on the other hand, sees life as though he is sitting in the NBC blimp watching the parade. He can see all of the performers, from beginning to end, as well as the twists and turns life is going to throw at them. We cannot explain this with our human understanding, because we have never experienced this perspective. Because God sees from beginning to end and knows the choices we will be presented, he can insert people and circumstances into our path to help point us in the right direction- It's our choice to listen or not.
One question I've been asked as a Christian (I'm not a big fan of the label, I feel it's been grossly mis-represented by 'religious' people) is- "The Bible says, you did not choose me, but I chose you. Doesn't that mean God condemned some people to Hell without giving them a choice since they weren't chosen?". The best explaination I've ever heard for this is: "To choose us, God looked into the future and saw that we would choose him, so he went back and chose us first by writing our names down in a book that was authored before we were born." It's something that cannot be fully understood by my limited mental capacity.
That's my personal take on the subject.