It's Vagabond. And I say this because in my mother tongue, this is essentially the same meaning, but it has very high-context negative connotation. I find it interesting that people use that term for themselves so quickly and willingly. There's so much more to that life that you talk about "before you had a family" and I, for one, can say I know exactly what you mean. The best word for me, though, was runaway wanderer.