Today is my little sister’s birthday, and at the finely seasoned age of 37, she is spending it at Naval Station Great Lakes, AKA Navy boot camp. I have visions of Molly being yelled at, and of her yelling right back. She is smart, and she is confident—and I know that she will be taking the initiative before others not just because she has been around the proverbial block once or twice, but because she has also done a fair amount of high pressure training before this latest iteration.

When Mother’s Day rolled around earlier this month, I asked friends and family what they found to be most surprising about motherhood. I got a lot of honest and humorous feedback, but response that struck me the most came from one of my older sisters who had a kid in her late 30s.  She said that motherhood “made me realize that I can go and go and go. Because there is no other choice. I’m stronger than I thought.”

I don’t have kids, but I think that I have a reasonable appreciation for what meant.  I think of my little sister rolling through boot camp, and then reflect back on my own experience at Officer Candidate School at the age of 22.  I’m 39 now and think that there is no way I could go through that kind of indoctrination now.  But she’s doing it, and we take a page from our older sister, she’ll keeping on going until she is through.

While Molly is just starting off her Navy adventure, I myself just spent the past week in a retirement course that will facilitate a transition from the same service at a not too distant date. Me, I’ve had my share of fun and challenge, but at the same time I feel pretty tired. I have visions of a retirement spent doing some other sort of job at a far slower pace, feeling somewhat anchored in a medium sized town with not as much bouncing from country to country.

But even as I fantasize about such a future, I then take stock of my 2017 OPTEMPO thus far, and I ask myself if this will every become a reality. Because while I’m tired, this doesn’t mean that I will necessarily slow down. Perhaps I’ll do something as unconventional as Molly, and embark upon something new that will test the limits of my well-worn habits and patience.  I’ll find myself digging deep to discover reserves that I previously believed to be non-existent.

I used to think that your 40s and 50s were old.  Like, really old.  The kind of age where you cash in the bulk of your chips and focus on developing your body’s midsection in such a way that it presses against your new set of microfiber polo shirts.  And I could be wrong, but it would appear to me that this notion no longer is the norm.

Maybe it’s because I am now an older person, and I’ve got siblings who spin through their lives like tops in a way that they never did in their younger years.  But I really do believe that humans are truly capable of staying younger longer if their brain tells them to do just that.

If I had a time machine, I’d love to skip back to observe my ancestors from each era and see what they were doing around the age of 40.  I could take stock of their energy levels to see if there was really less of a physical and mental demand.  Maybe at the end of the day it is all relative, and the nieces and nephews will one day have kids who imagine that we here spent our days playing croquet, or something decidedly slow. Not sprinting after four year olds guzzling nail polish remover or pumping out dozens of pushups in the rain while hollering the articles of the Code of Conduct at a boot camp.  Who knows.

For right now we’ve just got Molly’s birthday to mark, and I miss her. I’m also proud of her.  It’s Memorial Day and we have many high performers who came before us to remember, and I’m currently packing a carry-on and a standby plane ticket to continue my behavior as an overgrown teenage wanderer.

I’m tired, just like we all are, but we’ve all managed to find ourselves a sort of routine.  And Hell, if my sisters can continue to hack it, so can I. We’re all here to keep each other in pace, no matter how the years start to add up.