Something ISTP Profiles mention is that ISTP Children are explorers, which often continues into adulthood.
As a kid younger than the age of 7, I would wander off and go trapsing through the woods or follow a stream. Often with the family St. Bernard to accompany me...
I was notorious for sneaking out during nap time in daycare, when we were supposed to be on our cots. Sometimes I'd be out on the playground, an adjacent building or an adjoining neighborhood. Big dogs would sometimes scare me but I'd do it anyway.
As an adult when traveling for work or pleasure, I still wander off to check things out on my own. Just get out and see the sites, sometimes talking with strangers. So any other ISTP's on occassional walkabout?