Yes, that’s true the thoughts you have are not yours completely. If you live a life of awareness where you are completely present at the moment and the word called multitasking is not yours then you are the master of your thoughts living a yogic/spiritual life.
However, your thoughts are mostly borrowed by the outside world in different, different ways through your experiences, observations, and intellect but they are not yours. You have accumulated them over time, and you are very well aware of the law of attraction process in which thought vibrates at a certain frequency to create specific life for you.
When the thoughts which vibrate in your subconscious are not yours then the message which is transmitted to the universe through the law of attraction is not for you and certainly does not support the purpose of your presence on this planet in your current physical body.
Let’s not get involved in more of the algebraic calculations, simply learn by observing any child of 8 months and above First thing living the moment, secondly, no fear and the state is spiritual.
Go back into that state of yours where there is no multitasking and involvement is 100% in every task may be just crawling, laughing, or crying.
Own your thoughts and see the miracle.
If you find it difficult take help!