When I first started picking up bits and pieces of their conversation, I thought the elderly man and woman were talking about Christmas parties.

“Martha’s is at 4 but it’s in Cullman,” the woman said. “That wouldn’t give us much time to get back for John’s at 6.”

“I know,” her husband said. “We’ll just have to leave early at Martha’s and maybe be a little late for John. Neither one of them will hold it against us.”

Then I realized they weren’t talking about social plans. They were talking about funerals.

The man and woman were probably in their late 80s. They seemed healthy and were mentally sharp, but they moved slowly. They had a page of newspaper obituaries in front of them. They were talking about the loss of friends and scheduling of funerals the way a younger person might talk of juggling Saturday night dates.

It struck me that death didn’t seem like that big a deal to them. They must have experienced enough of death that it wasn’t a looming existential crisis for them. It was just a very real fact of life that was slowly coming to get every one of their friends — and coming to get them, too.

As I was processing what I had observed from them, I noticed a man come into the restaurant with his small daughter. The little girl was about 4 years old and she was curious about everything. As her father ordered, she wandered around by herself, picking up straws and bags of chips and random pieces of paper from the floor. Everything seemed to fascinate her.

They sat next to me — in the same booth where the older couple had been sitting — and the girl was a non-stop chatterbox of questions. Among other things, she wanted to know why it took Christmas so long to come. As her father tried to talk with her about time, something occurred to me — and I never would have thought of it if I hadn’t just heard the older couple.

The advance of time doesn’t frighten children. They’re too young and inexperienced to know how short their lives will feel.

The advance of time doesn’t frighten the elderly. They know they don’t have that much time left. They’ve mostly come to terms with what has to happen before long.

The rapid advance of time is terrifying only to those in the middle — those who are old enough to appreciate how short life is but who are young enough to still do something to change their lives.

I don’t think I’ve ever really understood the idea of a “midlife crisis” until now. People who experience such a thing don’t just suddenly turn selfish and want to ditch their responsibilities. (Although that might happen, too.) These are people who suddenly realize how different their lives are from what they imagined — and that realization has them scared enough to make immediate changes.

When I was young, I thought I had forever to do the things I wanted to do in life. You probably felt the same way. Even though we consciously knew that every life ends, we felt we had enough time in front of us that there was no rush.

But nothing about life seems to work the way I thought it would. The hopes I had haven’t come true. I haven’t accomplished the things I had planned. Much of what I’ve tried has been unsatisfying. And the love I’ve needed still hasn’t come to stay.

By this standard, I’ve been experiencing a midlife crisis since the time I was about 30. It was about then that I realized something was wrong with the way I’d seen life. I knew my life had to change, but I had to learn so much — and change so much about myself — that it’s been a terrifying ride.

I feel as though I was thrown out into the sky with a box of airplane parts — many miles above the ground. Ever since I realized that, I’ve been desperately trying to assemble an airplane out of these parts — trying to figure out how to build it and fly it before I hit the ground.

A young person doesn’t really understand what it’s going to feel like when he realizes he’s falling toward Earth. An elderly person knows it’s too late to do anything about it. But someone in the middle stage knows he can still do something to make his life what he wants it to be — and he knows how little time he has left to do it.

Every single day, we are closer to the day when our bodies will be buried in the ground. Every day we spend doing things that make us miserable is a wasted day. Every day we spend delaying the changes we know we have to make is a day that’s put us closer to never becoming what we want to be.

You have some idea what you want your life to look like. I do, too. Most of what we do gets us no closer to that life. If you ask yourself each evening, “Did today get me closer to what I want my life to be?,” the honest answer for almost every day is a hollow acknowledgment that nothing changed.

You keep thinking you have plenty of time to make changes later, right?

You keep thinking that the changes you need to make are too scary, right?

You keep making excuses not to make the changes — because there’s some tradeoff that scares you. Right?

Every child thinks he has forever. Every person near death knows it’s too late. And those in the middle know we can still change our lives — but we let fear stop us from doing what we need to do.

Time is my enemy. It’s your enemy, too.

I’m making some changes before it’s too late. There are other changes I need to make, but I have no idea how. I just know I’m hurtling toward the ground as I try to put this airplane together and make it fly before it’s too late.

I’m scared.

But I still have way too much to do and be and love before I give up and hit the ground.