This is an important guidance to judge and recognize "original" thoughts which lead one to his/her purpose of life. This includes high level of language. Every Word Counts as they are compressed... expand it as per your thinking.
It is difficult indeed to find a difference between our "original" thoughts and thoughts created as a response to a situation or under influence of vibrations/atmosphere/company of another.
Simple reasoning is > Ask yourself this question > "Is my thought reasonable, given by own knowledge, experience and situation?"
We all are a PART of world. However one tries otherwise, they would surely contribute to it. And get a payback from world consciousness.
Tip: LEARN about collective/world consciousness
The method to differentiate is this-
"Go within... Introvert... Remember Shiv Baba.... now you are in the company of Shiv baba... not thinking of any other soul, situation or world in general... The thoughts you get in this stage, are purely yours"
Think deeply... every imparted thought is always inclusive of another person, a life event occurred in past or worry of future. There is this thought process which keeps you engaged in thinking in a CYCLE... Remove other souls & worldly scenes from the sight of your intellect... what is left is ME... purely ME.
The rules of world drama does not allow us to be completely aloof (detached) from the ever-changing, ever-engaging world... but we souls have 2 powers: "Gyan and Yog" >> use the knowledge (gyan) and power of Yog to stable your mind, keep detached from the influence of other souls.
Meaning: When you are spiritually more powerful, you do not get influenced by the outside atmosphere and people, but you influence THEM with your vibrations and thoughts.
I highly suggest you to learn about Near-death experiences
In the company of the father (Baba), no other company (vibrations) stays... This is one method of purity of the soul, and the answer to your excellent question.
On Godly Service,
Samadhan, The Shiv Baba Services Initiative