Does Free Will actually exist? Is there a way to tell?

[Tonus]

I have a pet theory that much of the world's problems are due to people's inability to understand their own brain's functions and what role their conscious mind actually plays in their decision making, but regardless, I think that attempting to understand how our consciousness operates can only be beneficial.

I understand and agree with that. I just think that the issue can keep a person going in circles. Over the course of our lives we change in many ways. It may be a big change (switching ideological sides, for example) or a small change (deciding to change the flavor of coffee you buy). These are almost certainly influenced by something. Does that mean that we have free will (we are able to make changes based on new input) or that we do not (we are guided by that input and don't really have a choice)? Without the ability to go back and replay those moments, we end up with a solipsism, IMO.

Everything we learn about how our minds work can be fitted into that framework so that we can either easily answer the question or not answer it at all. I suppose we could assign a percent chance to any decisions we make, but to me any percentage higher than zero would mean that we have free will. Or it could be argued that we have "30% free will" and "70% external influence" affecting our decisions, which might be a valid approach in the end, though I think it would prove that we do have the freedom to make our own decisions.