Allow me this admission: I didn’t do much thinking Sunday about the 45th anniversary of man’s first steps on the moon.

I was too busy traveling home from a glorious weekend with my family.

And to be frank, thinking of that day saddens me a little. It’s not because of the event itself. The late Neil Armstrong’s first step off the Apollo 11 lunar lander was captivating at a level I’d never experienced. “One giant step for (a) man, one giant leap for mankind” became a mantra to be repeated by proud Americans everywhere.

No, the sadness comes in realizing where we’ve gone — or not gone — in the decades since then.

We landed a few more times on the moon, had a near-tragedy when Apollo 13 exploded en route — only to be brought home in a miraculous seat-of-the-pants rescue effort. Alan Shepard, America’s first man in space, got to land on the moon and hit that golf shot that went miles.

Those were heady times.

Then the missions became “routine.” How sad. NASA pulled the plug after Apollo 17. It embarked on the Skylab mission to test humans’ long-term endurance in space. Then came the space shuttle experiment, with its huge highs and devastating tragedy.

Then it ended. The shuttle fleet is retired. We’re piggybacking into space aboard Russian rockets.

I admit to longing for the days when we could get re-inspired the way we were when President Kennedy made it the national goal to “put a man on the moon before the decade (of the 1960s) is out and return him safely to the Earth.” We had that big, bad Soviet Union to race to the moon. We won that contest.

Now there’s some vague talk about going to Mars — eventually. Why “vague” talk? Because one hardly ever hears anything publicly about what’s going on. NASA engineers are toiling in obscurity — apparently — designing a vehicle to take humans to the next planet out there in our solar system.

My late mother and I spent many mornings awaiting the launches of the early space missions. Mercury and Gemini preceded the Apollo program. We agonized over the delays. Cheered at the launch. Wept with joy when the men landed safely in the ocean.

I’ve never grown tired of watching these vehicles lift off from the pad and roar into space. It pains me that the nation became bored with it.

I am grateful to have watched humanity’s first steps on the moon. I surely now want to live long enough to hear someone say, “Houston, we have landed on Mars.”