Travel is a set of unique experiences that form unique memories. Part of what’s addicting and pleasurable is that it helps slow down the perception of the passage of time, among many other positives.
It’s also self reinforcing in that when you think back, you tend to disproportionately remember travel vs other experiences.
There’s clearly a lot more benefits than that, but it certainly seems like a significant factor.
In general, I feel like most of my memories are structured around my unique (mostly travel-related) experiences. Oh 2015, that was the first time I ever left continental Europe and flew to Iceland in the middle of the semester to visit my friend. Things like that.