Nobody tells you that family vacations have an expiration date.

Not the trips themselves, of course. But the years when you can pick a week, book five plane tickets, and reasonably expect all five members of your family to show up.

Now my daughter is in medical school, my oldest son is in college, and my youngest is a senior in high school with a schedule that requires the logistical skills of an air traffic controller. Getting all five of us in the same place at the same time has become considerably harder than getting all five of us through airport security.

These days, I look back at the trips we took when they were younger with a new appreciation. At the time, they were vacations. Now they feel like little markers of our family history.

Some trips are simply better with a sweater.

Think brilliant New England foliage against a rocky coastline. Apple cider donuts after picking apples in the Blue Ridge Mountains. Ghost stories after dark in New Orleans. A train winding through the Smokies. Or hundreds of hot-air balloons rising over the New Mexico desert.

Before Bryan and I ever had kids, we started collecting ornaments from every destination we visited. We even picked up ornaments for big milestones — our wedding anniversary, our first home, the birth of each baby. (Nothing says “new parents” like a tiny glass onesie dangling from a branch.)

But once the kids came along? The ornament collection became a full-blown scavenger hunt in every new city. The kids got to help choose something that embraced the spirit of that trip — which is how we once came home with a London phone booth, a Venetian mask, and a tiny moose wearing sunglasses.

Now that our kids are teenagers and young adults, we have so many ornaments and so many stories — and Christmas decorating has turned into a full-on storytelling event. Here’s how it works: We each grab an ornament, one at a time, and share a memory from that trip before hanging it on the tree. It’s like speed-dating our own travel history.

And the stories? They do not disappoint.