I’ll soon turn 40, which I’m told is the new 30. But when I’m dealing with Millennials, I feel more like 70.

The first warning sign on my road to middle age was found on the car radio. About a year ago, I suddenly stopped blasting rock ’n’ roll and started quietly listening to talk radio—the news, or ESPN, or NPR. These days, I’m more likely to chill out to Prairie Home Companion than Pink Floyd.

And now, when some punk kid pulls up next to me at a stoplight with speakers blasting, the bass rattling my windows, I default to a disapproving glare that comes so easily to the middle-aged.

This is all part of the circle of life, I know. Yesterday’s rebels are tomorrow’s grandparents. But how long before I start using words like “whippersnapper”?

The older I get, the younger Gen Y seems. I love their sass, and tech-savvy ways, but their sense of entitlement is a bit much. They work an entry-level job and expect all the perks of seniority. They’re more likely to look at their iPhone during a conversation than the person actually speaking to them.

They love to dance but don’t want to pay the DJ. And I partly blame the student housing industry.

The sector has certainly evolved beyond the Animal Houses of yore, as you’ll see in our cover feature.

Granite countertops, hardwood floors, gaming rooms, yoga rooms, Wi-Fi everywhere. Hell, when I went to college, we didn’t even have cable TV.

In fact, my first dorm room in New York didn’t even have heat, a fact that my first roommate couldn’t cope with, so he moved out after a week. Yet I stuck around.

The school made me sign a waiver, which basically said my family couldn’t sue them should I freeze to death. I was all too happy to sign it. I bought a space heater and was the only kid on my block to have my dorm room all to myself.

It gave new meaning to the term “cold comfort.”

When I moved off campus the next year, it was a brownstone located “on the other side of the tracks.” Rats and roaches became our unwelcome roommates. And somehow, far from the lap of luxury, we still learned a thing or two (above and beyond how to set a rat trap).

And now, listening to myself bitch and moan about my relative “hardships,” I’ve officially become my father.

Youth is celebrated by our culture, romanticized beyond belief. We see it as a golden time in our lives, a neverland of careless joyrides before the weight of responsibility humbled us into morning commuters.

Likewise, Gen Y is often celebrated by our industry as a driving force behind a never-ending upturn, a ­gravy train we can ride to new heights of profitability. But maybe we should temper our expectations of them, in the same way that today’s students should temper their expectations of us.

Once they enter the real world, Gen Y may not be able to afford the luxury they’ve grown accustomed to in college. And apartment owners may not be able to charge the kind of rents they’d like to charge to a demographic hamstrung by garnished wages.

The student debt crisis may be the next great bubble to burst. The unemployment rate for those under 30 is more than 13 percent. Employment rates for those 18 to 24 are now at an all-time low (54 percent). Eighty percent of Americans, in a recent Pew Research Center poll, said it’s more difficult for Gen Y to find a good job than it was for their parents.

And let’s not forget the cycle of life: Gen Y, too, will gradually morph into their parents, as I have, and buy a house out in the ’burbs.

Gen Y may be the goose that lays a golden egg, but a word of caution: Just like in a supermarket, you need to double-check those eggs for cracks before you spend your money.