When I was a kid, I used to love walking on railroad tracks.

As an adult, I still did it whenever I had the chance, enjoying a remnant from my childhood, I guess.

Balance was something that came easy. So was flexibility. But my best strength was aerobic capacity.

I've always loved to move fast. Still do. And aerobic classes and fast-paced Zumba classes are still favorites of mine.

But over the past year or two I've been dismayed to see my balance isn't as good as it used to be. At the gym, when I'm in a class doing exercises that require balance, I find my body shaking as it struggles to center itself when I stand on one leg.

My once-prized aerobic ability is faltering, too. I've had to stop taking Zumba classes with much younger women. Instead, I take Zumba Gold with women around my age.

When, I wonder to myself, did my gym strengths erode to this extent?

At first, I worried this might be early signs of a disease. Actually, it's just signs of aging.

Like everyone else who finds the door called youth has slammed shut, I have to accept that there are skills I no longer have not to the extent I once did.

As we age, our bodies lose balance, tone and a whole lot of other things. I hate it. No one likes to accept he or she can't do physical activity as they once could.

But here's what I've been thinking it all balances itself out. We do, indeed, lose some things as we age. But we gain some good things, too.

Perhaps the most important thing we gain as we age is the ability to know what's important and what isn't.

It's not an inconsequential skill. It's life changing when we gain that knowledge.

Here's why:

When we know what's important and what's not, we have more peace and harmony because we let little things go by.

Many people have observed older people are more tranquil. That's not because their minds went to sleep. It's because the tranquility comes from wisdom gained through the years.

You've heard the expression: Too soon old. Too late smart.

That's one way of saying we do, indeed, gain valuable wisdom as we age. If we would have had that wisdom decades earlier, life would have been smoother.

As we age, we learn to look at the big picture. We don't focus on the little burrs we encounter.

The wisdom we gain teaches us life isn't all about "being right." Slights and disagreements don't consume us as they once might have. Instead of harping on an issue, we remember the person is more important than the act. We learn to let a lot more go by without reacting.

Friends of mine just celebrated their 50th wedding anniversary. I asked them what has made their marriage so strong.

"We overlook the small stuff," said my friend, "and mostly, it's all small stuff."

You've heard that before. There's even a book by that title: "Don't sweat the small stuff (and It's All Small Stuff."

We read it and hear it. But we don't truly take it to heart until the wisdom of age mellows us.

When my father was a young man, he was what we call "a hot head." He got in fights with people and his quick temper ruined his marriage.

Years later the temper was gone. In its place was the wisdom gained through the years. Looking back at his life, he said he wished he could have been mellower when he was younger.

Older people take more time for kindness, too. We stop running through life and stop rushing by people as if they weren't there.

It all has to do with learning, I guess.

We have learned that love is a renewable resource. The more we give away, the more we have to give.

I saw a survey the other day that concluded older people (defined as 65 and older) are happier and more content than younger folks. The article went on to list a lot of reasons why, focusing on the fact that in retirement we have time to do what we want.

I think the article missed the main reason we "older folks" are happy: We've gained a true sense of appreciation for all of life.

If I could name the main strength we gain as we age, I would put appreciating life at the top of the list.

When we are younger, we miss much of the beauty of each day. Sure, we appreciate what we have. But as we age, that appreciation takes on a sharper focus.

We take time to appreciate the small pleasures of each day. We don't gulp down a cup of coffee in the morning before we rush off. Instead, we savor that first cup of coffee as the first pleasure of day.

We take in every detail of life and relish every bit of it.

As we age, we become more introspective, looking back through the years at people who have shaped us in one way or the other.

When I do this, I feel a rush of gratitude for so many people who have touched my life. I may not see them anymore, but I carry them in my heart with love and a keen sense of appreciation.

When we're older, we learn not to take life for granted. We treasure the gift of each new day.

For all that we lose as we age, we gain a whole lot more.

What have you gained as you've aged? Share your thoughts.