Practicality and passion.
I started out physics and liked it somewhat but not really.
I took business classes and enjoyed them-- financial analysis etc. It is a very competitive field and I did an internship and didnt enjoy it. Plus much of that cool financial analysis Black Scholes equation stuff, valuation is done automatically by computer programs like DealMaven or Goldman Sach's modified version that no one can get hold of except for them. For that they have computer programmer quant guys working for them.
I am doing an internship in business/tax law some securities stuff, tax returns, estate planning. I like it a lot - can be difficult because it is very technical, lots of rules, and in volume.
I'm also a greedy son of a ***** and it pays a ton of money. But since I like the field its good. So a mix of practicality and passion. However, I urge practicality.
I hear too many stories of people having tough times getting jobs with their majors. Unless you are really really realistically good or at a top school I urge you to stay away from the more liberal arts majors unless you plan on law school or medical wih science prereqs. Hate to say your parents told you so.
We live in an expensive capitalist society for which there are great opportunities and benefits. There are also disadvantages. For the people who work steadily and choose the route less taken, well needed, and harder there will always be tons of payoff.
Your dreams will take time.
I have thought of stuff like having a tax/estate planning practice in a place like Aspen or Steamboat Springs or Park City, Utah but it will be many years before I can do that. I LOVE to ski and that would be a dream. Might not happen until I am 45 or 50.