I know a lot of my peers knew in high school and ended up doing what they thought they would.
I work with labor force data for a living so I have access to lots of good data at the detailed occupation level (average wage, entry level wage, experienced wage, education requirement, historical growth, projected growth, unemployment rate, etc.) We also map degrees to occupations. We would not map an art history degree to IT management.
Kids may not know exactly what they want to do but there's a lot of information available to help them make good choices. If they want a six figure job, Art History probably isn't the way to go. All the one person case studies (mine included) don't change that.
No, you wouldn't map that, yet I know IT managers with degrees in Art History, Theatre, Anthropology, History, English and Sociology. And some with degrees in Business (long after I became an IT manager, I picked up a business degree as well). I can't think of anyone who got their undergrad degree in Computer Science or MIS - those people tend to end up being developers, architects, etc. (Masters, yes. Which is another thing - we are talking undergrad degrees. Most managers have an MBA - I don't, but most do. You can pick that up with any undergrad degree. And it IT, MOST undergrad degrees for managers are liberal arts, in my 35 years of experience in the field working for Fortune 500 sized companies.)