Editor's note: Annette Miller is one of six CNN viewers selected to be a part of the Fit Nation Triathlon Challenge program. Follow the "6-pack" on Twitter and Facebook as they train to race the Nautica Malibu Triathlon with Dr. Sanjay Gupta on September 8.
(CNN) -- You never know who's watching. As a child, I always thought this saying meant I had to make sure I was on my best behavior when grown-ups weren't around to make me mind.
Over the past year, however, the phrase has taken on new meaning for me.
In January 2012, I joined the Y and started the journey of my life. I had already been walking and working on small changes to my diet. I was determined to become the emotionally and physically healthy individual I deserved to be.
I was beginning to figure out I was worth my own time and effort.
At first my decision seemed selfish to those in my family who were used to having all my attention. When I couldn't pick up a prescription, pay a bill or go to the store for them because it was gym time, I was being self-centered. I was about to discover my family members weren't the only ones watching.
I'm blessed with close friends who are all health conscious and actively fit. One of my dearest friends, Anje, had been watching me for six months and said, "Let me help you."
Those are the four most powerful words I've ever heard. I didn't know how much I needed help until she was there every day. She taught me how to work out effectively and safely; she pushed me when I couldn't push myself. But the best gift of all was her friendship. I was now the one watching.
By the end of 2012, I was at the gym six days a week. The weight was melting off, and everyone was noticing.
My co-workers would ask, "How much?" My family finally realized that being healthy was a serious and necessary transformation. My friends told me how proud and inspired they were.
It was one thing for people I know to watch, but people at the gym had been watching, too. One day Anje and I were working on biceps when one of the regular weightlifter guys came over and said, "We are here every day and we see you every day. We just have to say your transformation is amazing!" That was one of my proudest and most humbling moments at the gym.
A few weeks ago I was running. I had been sick earlier in the week, and it wasn't a good run for me. I was thinking about walking my fifth mile when a stranger came by and said, "You're killing it." I ran that fifth mile thinking about mind over matter.
My relationship with my sister Judy is strained, so the idea that anything I do could affect her is shocking. Judy decided a few months ago she wanted gastric bypass surgery. I don't agree with it, but I never tried to talk her out of it. Trust me when I say weight loss is more mental than it is physical. The physical part is easy; changing your mind is the challenge.
Imagine my surprise when a few weeks ago, Judy told me, "I've been watching you, and I've seen the weight loss. But I've also seen how happy you've become. I've decided I need to work on my mind and not just on losing weight. You've done it right, and I'm trying your way first."
She's been watching the whole time.
I spent all of 2012 working to become healthy in mind and body. I'm continuing that journey into 2013 with CNN Fit Nation, and it's one I will continue for the rest of my life.
I never knew simply taking care of myself would have such a widespread effect. Now when I hear, "You never know who's watching," I realize it means I need to live life by example.
I may just change another life in the process.
Follow Miller on Twitter @TriHardAnnette.