I think it would do you a world of benefit to simply expand your horizons a little. Rather than focusing on what to study, try your hand at different ways of thinking. This will help you identify what you're interested in so that you can make an educated choice for yourself.
For example, if you're an imperative programmer, then read up on functional programming techniques (Monads and category theory in FP will unlock a whole world of knowledge that will help you better understand things like Observables, Promises, Immutable collections, etc) as well as teach you how to use a Y combinator to implement recursive functions in languages that do not support recursion. If you find you're interested in this, then perhaps a mathematically involved university course will be something you're interested in.
If you're used to SQL and NoSQL databases, then learn a Graph database. That'll expose you to concepts useful when dealing in the Big Data realm (heavily used in market research, social networks, traffic analysis, etc). Maybe a statistically involved university course will be of interest to you if you like this stuff.
Try learn a language with a syntax that is incomparably different to the one you're used to writing (i.e. if you're primarily a Java/C# type person - then try Haskell or Python - something where the syntax differs quite a bit) - this won't really help you identify anything worth studying at university, but it will make you a better programmer, because you'll be able to borrow concepts from one language and abstract them into another (should you need to) if they lack the functionality you need for whatever use case.
If you write your code top-down (define a function, then use it), try writing it bottom-up (use a function first, before you define it later on) instead. If your programs tend to slowly transform initial data into a result, try to instead derive the initial data from the result you expect (i.e. work backwards) - that's something that will be to your benefit in regards to teaching you how to write more elegant code.
At your age, I wouldn't worry too much about working for Google. I think that if you already know what you know (which is impressive), and you keep thirsting for knowledge (like you are/have been), there's a very good chance you'll achieve your goal. :)