I remember when someone told me that there's "no such thing as an original thought"

It drove me nuts thinking about it, and I can't believe that it's true. But I do believe that all thoughts are reactions to stimuli in some form, no matter how remote or indirect. Each thought comes from a completely different line of actions/reactions that lead us to have the thoughts, so in essence they are all unique, yet often times strikingly similar. Most things are governed by the same mathematical ratios, so it's no wonder that many thoughts end up being a lot alike which would lead people to believe that things were "destined" to be thought of... it's just really good probabilities at work.