I don’t know what my son thinks of the idea of turning 30. I know what I think. I think it’s just plain weird.

It wasn’t so long ago that the pilot would boost our little boy — or his sister, whoever’s turn it was — into the front seat of the airplane, a little child’s head lost in a big headset, and the pilot would “let him fly.” It doesn’t seem long ago that he was a tot in rubber boots and a homemade pullover sweater, sitting on his dad’s shoulders, headed for the tide-pools or the powerhouse.

My older child, who grew up on Matinicus but has lived in Vermont since college, turned 30 this week. That is messing with my head just a little bit, but it’s alright. All is as it should be.

Thirty in our culture is one of those landmark birthdays that’s got more baggage attached than it should have. “You’re not a kid anymore.” We ought to react with a sense of long-awaited freedom: “Good; that means I can do what I want now. I can finally make it clear to everybody that I don’t like broccoli, or skim milk, or corned hake and nobody will suggest that I will later, once I grow up.” Instead, we have to shoulder an obligation. “Get your act together. You’re behind. Pull up your socks; there will be an inspection soon. Have you accomplished things on your list? Probably ought to start a 401k. Also, eat more broccoli.”

If you’re the mom, it’s weird. I’m telling you.

The experience of one’s children pulling out ahead in various things as the inches add up, and overtaking your own grown-up knowledge or ability before they are grown themselves, is peculiar, but it is ultimately satisfying. A wise friend reminded us once that the real point of parenting is to work yourselves out of a job. If we’ve done it well, the kids likely won’t need us much after a while. If we’re really fortunate, we’ll enjoy each other’s company without them showing up with their laundry, or us offering unsolicited advice about what to eat for breakfast.

I first felt that strange sensation of my children leaving me in their dust when I sat on the YMCA bleachers and realized that Eric, at some single-digit age, could swim better than I could.

A few years later my kids — in their element in the water — along with their friend Jake rescued a swimmer caught in a frightening rip current. There were no adults around at the time. I’m still genuinely proud of all three of those kids, and I’m relieved that I wasn’t on that beach, inevitably struggling with my parental duty to keep them away from danger. I couldn’t have done what they did.

I can’t snowboard, either. The first time Eric tried it was when I took him to the Snow Bowl. He wiped out, but all he really needed was lunch and maybe a little cheerleading, and by the end of the day he was eager for next time. I stress fractured both my thumbs and haven’t done it since. He became a snowboard ski patroller at Sunday River.

I really felt it when Emily took calculus. Those two were breezing by me like I was up on blocks.

People say things about grown children like, “No matter their age, you’re still their mother,” or “No matter their age, they still need you.” I don’t know. I have a friend with grown children who says, “If the phone rings at 2:00 in the morning, a mom always panics that one of her kids has been in an accident.” I don’t; I worry that there’s a fire, or someone got up for a drink of water and peeked out the window in the dark to notice another guy’s boat taking on water, or somebody’s in pain when there’s no way off the island in a storm. I know better than to think that if my kid is broke down by the side of the road in northern Vermont he’s going to call his mother on this island. What rot; he’s going to call Triple-A.

I do like the idea that I can ask my kids about stuff that I don’t know anything about. A couple of years ago, I took an introductory sea kayaking class at L.L.Bean, where we learned how to do a “wet exit” and self-rescue. The instructor was our daughter, who is a kayak guide. Of course, I don’t often have reason to ask how to snowboard, or work a differential equation, or pick out a good Scotch or rig a Source 4 Ellipsoidal or understand the intricacies of borosilicate glass but, should I ever need such advice, I know where I can get it.