I think most people who go to university don't know what they want to do at 18.... and some of us still don't!
University never used to be about finding a career or a job. It was a place for higher learning and then people who had that higher learning were considered to have a liberal education to be able to learn and adpat to the job they chose. Universities used to be about studying the classics or sciences
Now, its more of a trade school.
You study business or dentistry or engineering.. very specific things..
Most people I know who are my age, twenty eight and over are doing something COMPLETELY different form what they studied at uni nearly 10 years ago.