Between the ages of 15 and 17, I lived in a house which was a couple of miles from the nearest town. The road between home and town was not exactly hilly, but it was gently undulating, and I only ever cycled into town along that road twice.
The first time, I was a little disgruntled to find that the journey appeared to be almost entirely uphill in both directions.
Six months later, the same journey was almost entirely downhill both ways.
How could this be? Well, obviously, the road itself hadn't changed. I wasn't any fitter than I had been six months previously, and I was riding the same bicycle.
The change was within myself, and it was that second bicycle ride which brought home to me how much I had changed in six months. In my early teens, I tended to focus on the negative, to make heavy weather of the uphill stretches, to expect the worst and be unsurprised when it happened.
Since my late teens, I have started to focus more on the positive, appreciating the freewheeling times of life and gradually developing a state of deep contentment and gratitude at the way my life has turned out - despite the fact that it is currently nothing like the dreams that I had for my future as a child.
I'm sure that in large part the thing that brought about this difference was prayer. Not just any prayer, but the simplest one of all - the one that I have said every night since I was about 16 and have taught my niece to say:
"Thank You, God, for a lovely day."
There were times when it stuck in my throat - it had been an absolutely dreadful day, everything had gone wrong, I was angry, miserable and uncomprehending about things that had happened during the day. I could thank God for giving me the day, but how could I call it a "lovely" day?
But I forced myself not only to say the words, but to mean them. And meaning them often meant searching through everything that had happened during the day and finding something for which I was grateful.
I still do it, and even on the very worst days of my life (and by the time you reach my age, you're pretty unusual if you haven't had some fairly dreadful ones), I have been able to find that thing - the support of someone who listened and gave me a shoulder to cry on, good weather and good health so that I could walk/run/cycle off some of my frustration, or even simply that the bad news wasn't even worse, and that there was still some hope.
It's the simplest of prayers - the words aren't fancy or complicated, and even a two-year-old can say it and understand it - but it's probably been the most important in shaping the way I view my life.
And isn't that yet another thing that I can be thankful for?