The first time we traveled internationally with our kids (a 5-year-old and nearly-2-year-old twins), my wife and I assumed the kids wouldn't really care, but we'd go anyway because we didn't want to give up international travel for a few decades just because we have kids.
They absolutely loved it. Now the 5-year-old is 15, they've been joined by a couple more siblings, and (Covid-execepted) we've gone on at least one international trip every year.
One of my favorite lines from one of my favorite books is in "A River Runs Through It" when the narrator says, "When I was young, a teacher had forbidden me to say "more perfect" because she said if a thing is perfect it can't be more so. But by now I had seen enough of life to have regained my confidence in it."
I recently went through a decade of photos to see if I could unearth memories of the "more perfect" moments in my life. Nearly all of them were on those trips with my kids.
There's something uniquely "us against the world" about international travel as a family. Not that we approach the world antagonistically, but just in that traveling across borders, and making our way through airports, and figuring out unfamiliar mass transit systems, and navigating unfamiliar cities in languages we don't speak requires a level of coöperation we're not usually called upon to exhibit as a family.
I'm sure there are times it's brought out the worst in us, but they're far, far outweighed by the times it brings out the very best parts of being a family.
For the coming summer I've promised to get the two oldest (now 18 and 15) plane tickets to Madrid, Interail (Eurorail) passes, and flight back to US from Helsinki 3 or 4 week later. They'll figure it out, have fun and hopefully don't do too much dumb stuff. Way to bond before the oldest one leaves to college. The middle one gets to do similar trip again in 3 years when he graduates with his younger brother; who in turn will have his trip one year later (hopefully his oldest brother will be available to join him so that everyone will end up with 2 trips with each of their brothers).
What do they remember? Almost nothing before they were 10 years old. A core memory here or there, but they can't even recall entire trips from then. But I've always just considered it as part of their development. Maybe they don't have actual memories, but who can say how else it developed their brains?
My 5yo regularly flies across the world back to my home country, but it’s just another place to him. The important thing is that his uncle is there, not that it’s on the other side of the world.
There’s no concept of going to the other side of the world, beyond it taking ”a very long time” to get there. And why would it? The plane might as well be a teleporter.
I _still_ remember all that travel too. It was different enough to make a lasting impression.
99% of our life is spent in the same 2 sqkm area, so it’s not super surprising that everything else is different.
I've said that it doesn't matter if they remember it. It's much more important that they experience it.
You can only experience Rome as a four-year old when you are four years old, there is no chance of getting that experience ever again their lives. They can experience Rome again, and again as an adult if they want, but being 4, 8, 12 or teenager at new place is not something that anyone has a chance of ever repeating.
They remember somethings, forget others, but come away with an interest in people, places, environments, etc.
Our niece supposedly remembers life before our oldest. She was 3 when she was born. I think a big difference though is she had the continual disappointment from then on of not being the only grandchild.
Later, I took my three kids to Barcelona and Greece. They don't remember the time we took a bus from Athens to the beach and they were rolling around on the dirty floor of a bus, but they do remember the Abba-themed wedding.
Those experiences matter.