"Kicking a bad habit is about rewiring your brain."
To many people that "rewiring your brain" part probably seems like an overstatement, or a little dramatic. It's not. There's a well-known, well-researched field of science dedicated to just that: neuroplasticity, or brain plasticity.
Neuroplasticity is the brain's ability to alter its connections — to re-wire itself. Without this ability a person's brain wouldn't properly develop from birth on through adulthood. It also wouldn't be able to recover (to some degree) from a brain injury.
One of the best things about neuroplasticity is that while it lessens with age, it never ends. No matter your age, you can still encourage your brain to remain "plastic." That improves memory, allows you to process information better, improves communication skills, and can even lessen anxiety and depression.
There are nutritional supplements that help with neuroplasticity. But there also simple, non-drug and non-dietary ways to keep your brain developing new pathways. Reading a book (especially fiction) helps. Continuing to learn helps. It doesn't really matter what it is you're learning - it's the process of learning, and practicing, something new that makes the brain stronger.