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.
My theory is that everything takes a little longer as you get older, but in very small increments, so you don't really notice it. E.g., getting ready in the morning takes just a few seconds longer each day as you get old and slow down, but you remember it taking a set time, say 30 minutes. Then one day, you're up to 40 minutes, but it still feels like 30 to you. Aggregated across your myriad daily activities, and you're either getting the same amount of things done in a day, but your day is "shorter", or you're just running out of time altogether, because "where did the time go?" So, you perceive that time is moving faster, because you're getting less and less done in the same span.