Our thoughts are mainly controlled by our subconscious, which is largely formed before the age of 6, and you cannot change the subconscious mind by just thinking about it.
The future is to heal back to the mind again. Recognizing that the mind is all powerful - it controls every cell to every degree of its genetic expression.
Through consciousness, our minds have the power to change our planet and ourselves. It is time we heed the wisdom of the ancient indigenous people and channel our consciousness and spirit to tend the garden and not destroy it.
If we could get your subconscious mind to agree with your conscious mind about being happy, that's when your positive thoughts work.