I went into college thinking I would major in math/CS but switched to Economics by the spring of Freshman year. I was interested in business, and Economics seemed like the closest major available. Turns out that it really doesn't have much to do with business at all. In retrospect, I wish I had stuck to my original major!
There was a recent episode of Planet Money that pointed out that peoples' choice in majors can have a huge impact on their earning potential.
<<Sure, some college degrees lead to higher paying jobs than others. But what's shocking — at least, it was shocking to us — is just how big the gap can be.
The most lucrative majors typically lead to jobs with salaries over $100,000 a year. The least lucrative lead to salaries of around $30,000. >>
http://www.npr.org/blogs/money/2013/09/11/221417806/episode-485-whats-your-major
Totally obvious in retrospect, but at the time I was just picking topics that were of interest to me!
What year of college did you pick your major... and why did you pick it?