I've actually done that, and still feel the urge to do it nowadays, except I am already at university, which sadly has brought more distress than joy, at least for the past year.
Earliest time I can recall was when I was 8. I went with my grandparents hiking after I recovered from meningoencephalitis (essentially dodged death) wanting to die, so I estranged myself from them. They found me after 2 days again, thanks to the village hounds.
I did something similar when I was 17, except I knew my destination. I couldn't stand dealing with some issues that I remember boiling 5 eggs, packing some ham sandwiches, 2 bottles of water and plenty of apples, some clothes and soap and I just ****ed off, to my mother's despair.
I had little to any money, so I couldn't afford any transport, so I just walked. I ended up walking 40kms until my mother traced me after 2 days. 10 more and I would have reached my grandparents, which was my intention. They lived a pretty recluse and tranquil lifestyle. Modest, but it had all I needed at the time (even now, I'd argue).
Something of the sort happened last year too. One night my anxiety was so overwhelming that I packed a suitcase and took a nightbus up to nottingham (the last stop). I've only been in that city once, so I had little idea about the place whatsoever, but there was something in that that was reassuring; kind of "losing myself in my surroundings", if you can call it that way. One of my old friends actually found me there, roaming around and drove me back after 2 days.
I still feel this compulsion every now and then, but I'm just trying to act more mature with my life and all that I'm facing. There's also a "living anchor" that's keeping me still now, so I guess I wouldn't consider an escapade alone now, if I needed to disconnect with the world