Reddit mentions of The Secret of the Yoga Sutra: Samadhi Pada

If a beginner gets on a tightrope, they will be lucky and sometimes have perfect balance. It may be fleeting. The more they practice, the less they will find that perfect balance, because now they're trying to find balance. Eventually, with all this practice, they will learn to find that state where they're not thinking about balancing, but are simply being balanced. So although balancing takes effort, you are actually surrendering into the state of being balanced.

I don't think it's a good idea to believe people who say it is without effort. Sitting and doing "nothing" is very effortful - all of the cells of your body and your emotions and your spirit are all synchronized to allow that sitting to happen. All of your multitudes are aligned at "optimal mindfulness".

The first 20 or so Yoga Sutras are very good at explaining the concept of vasannas and samskaras, which is the science of what you're asking about, if you want to go deeper on this subject. I highly recommend this particular translation as it's written by a wonderful teacher who teaches in a very practical Western-relatable way.