"Such as are your habitual thoughts, such also will be the character of your mind; for the soul is dyed by the thoughts."

• Marcus Aurelius

There's two images that arise when I consider habits of thought - one is a well worn sheep track on a hill, and another is a river stone, cool and hard in my palm.

Why don't the sheep take any other path down the hillside? Such is their habit that they don't stray on their descent or meander to the top. So it is with our thoughts. We travel the same way so often the neurons don't fire elsewhere. What we tell ourselves, over and over, becomes so well worn that any other path is seemingly impossible. It's why I think neuroscience should be a compulsory subject in high school. If only I knew then hos bullying was changing my brain to believe I wasn't worthy, and how much this would become a sheep track, bereft of grass. Perhaps I could have trained myself early on to take some different route.

But such is neuroplasticity that we have the ability to find new pathways, if we work hard enough. It's what the ancient yogis and meditators knew. Notice the thought, but don't react. Notice the path, but don't travel down it. Over and over and over, until the path grows over with grass and wildflowers, and a new one is carved, hopefully an easier, sunnier one.

Nothing is unless we think it.

I am worthy. I am kind. I am intelligent. I am creative. I am empathetic. Repeat after me. Say it until you wholly inhabit it.

I take the rock in my palm, the one that I have created myself. It started with a grain of sand, and gathered other grains until it had heft, fired my the heat of my thoughts. Each grain was the same thought, over and over. This time I lower it into the rushing river, allowing the water to begin to wear it down, the grains coming apart one by one until they disappear into the sea. The rock is tiny now, still solid, but not so much a burden in my pocket. I must be careful, I tell myself, not to create more rocks.