I groaned to my girlfriend after we drove by hordes of St. Patrick’s Day patrons last weekend, and I commented on how crowds and potential hangovers sounded unpleasant.

That same weekend, she and I gave a teenage family friend a ride and peppered in a few prying questions that made us sound like — wait for it — worried parents.

So when we were antiquing a few days later, it was no surprise that she just laughed when I joked about spending the last days of my 20s partying and living it up.

Yes, dear reader, you are reading the column of a newly-minted 30-year-old; I’ve entered “my fourth decade of life,” as my girlfriend relishes in reminding me — even though she is in her 30s, too.

I keep waiting for it to hit me, the pangs of panic at the thought: 30.

While writing this column in the final days of my 20s, I remembered a mild sickening feeling during the final days of my teens, but I’ve only managed a shrug at the thought of 30. But I’ve repeated the passage on turning 30 in F. Scott Fitzgerald’s “The Great Gatsby” several times in my head:

“Thirty — the promise of a decade of loneliness, a thinning list of single men to know, a thinning brief-case of enthusiasm, thinning hair.”

Well Mr. Fitzgerald, my hair is thinning and I know fewer single men, but I hope to avoid the “thinning brief-case of enthusiasm” and “a decade of loneliness.”

That St. Patrick’s Day experience reminded me how thinning has been a theme late in my 20s.

For starters, I’ve been more interested in my health and fitness in the post-college years, but my focus and interests have both narrowed throughout my 20s.

Closer to age 21, I’d have been excited by the promise of a night out on St. Patty’s Day. Now, I muse over how many more miles I’d need to run to burn those empty calories.

Instead, one exciting part of that weekend was — wait for it — starting a 12-hour grammar lecture. Yes, I am listening to  and enjoying  a 12-hour lecture on grammar.

Sorry, ladies, I’m taken.

But that’s another way that as I’ve grown busier, I’ve focused on maximizing my time by focusing on positives and practical things, which I appreciate more than I’d like to admit.

I wrote last year about my most-used Christmas gift of 2015. It was an ice-scraper with a brush, a gift from my sister, that I used all winter. Guess what, it’s still in my car getting frequent use.

My sister won again in the useful category of 2016 Christmas gifts with a coffee thermos that keeps drinks warm or cold for hours.

What are my fun Christmas presents up to? Let’s not talk about it.

And I’ve found I have a more discerning taste and appreciate good things, while my patience for mediocre books is waning. But I still occasionally need mindless entertainment. Who doesn’t?

After finishing “The Lord of the Rings” last month, I wanted to read a fast-paced bestseller. So, I bought “The Runaway Jury” by John Grisham on Audible. About a third of the way in, I returned it.

But I’ve seen the movie and know exactly where the story is going. Why bother? Instead, I’m listening to a Michigan professor/linguist lecture on split infinitives and prepositional phrases and so on.

Perhaps I’m just maturing, but simple joys gradually take on more complex values.