I'm learning that there are many ways, in fact, to do just that. But here are a few ...
With meditation I can retrain my brain, relax both my mental body and my physical body, and actually completely physically change my gray matter. A quote from this blogger at the NY Times fascinates me:
M.R.I. brain scans taken before and after the participants’ meditation regimen found increased gray matter in the hippocampus, an area important for learning and memory. The images also showed a reduction of gray matter in the amygdala, a region connected to anxiety and stress. A control group that did not practice meditation showed no such changes.
Learning something new is another way to exercise my mind. This comes naturally to me, I'm an overly curious person and I simply want to know how to do everything. Not necessary perfectly and to be an authority in every little thing in the Universe rather to have experience and familiarity with a huge variety of topics. There isn't much I won't try, even if it gives me a brain cramp like taking line-dancing lessons seem to do.
Positive affirmations are another useful tool. I have several CDs I listen to and a treasure trove of books and I write my own. I usually have an index card with affirmations written on them and they are never far from my person. When I get in my car (and I'm alone) and it is warming up I read them out loud. Sometimes when I am stopped at a long light. The index card I had in my car seems to be missing now and I had this visual of someone picking it up and looking at it and thinking "What the heck is this?" It made me smile. I'll have to write another for the car...
It has taken me a few years to become comfortable with affirmations and I am still improving in that area. One thing that helped was hearing Louise Hay's Affirmations CD where she explains that everyone uses affirmations, because every single thought we have is an affirmation. The thing is, most of us aren't aware of our thoughts enough to note whether those affirmations are positive (I'm grateful for the good things I've seen and done today...) or negative (I'm having a BAD day!).
I'm learning to tune in and change the station now. How many times have you thought you wouldn't be good at something, couldn't change something, couldn't do something. It is an affirmation, and I've been guilty of repeating the same negative ones over and over in the past. It is good to say "in the past" and know that I'm paying attention now and making changes.
Choosing better thoughts,
Breathing in, I calm my body.
Breathing out, I smile.
Dwelling in the present moment,
I know this is a wonderful moment!
Breathing in, I know I’m breathing in.
Breathing out, I know
as the in-breath grows deep,
the out-breath grows slow.
Breathing in makes me calm.
Breathing out brings me ease.
With the in-breath, I smile.
With the out breath, I release.
Breathing in, there is only the present moment.
Breathing out, it is a wonderful moment.
--Thich Nhat Hanh