I think this needs some context. I felt much the same way when I decided on a college, and made my decision based on that. I won't exactly say I was wrong, but 7 years later I've got a better perspective on the tradeoffs involved.
Understand that your raw intellectual prowess is a depreciating asset. I'd guess that I peaked in programming ability at about 19, and 18-20 seems a pretty common age range based on famous programmers. I'm certainly not as productive a programmer as I was at my first professional job at 19, and my 35 year old coworkers have said that there's no way they can keep up with what I do now at 26.
You continue gaining experience for a while after that, so it's not like you're over the hill at 20. The mid/late 20s seems to be the "sweet spot" where you still have decent technical prowess and yet enough experience to avoid blind alleys. But if you fritter away your early 20s, you lose the benefits of high ability and don't have the experience to show for it. You're starting behind and have to play catch-up to more youthful and more energetic competitors, which is possible but can be kinda discouraging.
OTOH, trying out a variety of things gives you a lot of perspective on what you do or don't want to pursue. I was certain I wanted to be a physics major and then a theoretical physicist when I entered college. I flirted briefly with majoring in philosophy or sociology when it turned out physics was much harder than I bargained for. I tried out fiction writing and found I wasn't any good at it. I made all-state violin in high school, but again realized that I didn't have the passion for it needed to be a professional.
The one downside of having all those options open is that I never finished anything. There was always some other avenue that looked more attractive. It was only in my senior year, when I was practically flunking out of physics and had a bunch of hobbies that weren't all that useful, that I decided I was gonna close off all the other avenues and focus on computers. And it was only then that I started actually producing stuff that was useful.
So, I'll agree with the parent post that it's important to grow creatively, socially, and intellectually in college. But understand that there are doors that going to Stanford/Harvard/MIT opens, and those doors tend to slam shut afterwards. It's possible to prop them back open, but it takes a lot more effort, because you're working against people's expectations. Similarly, there're doors that open from focusing deeply on one field, and it's much harder to achieve mastery in a subject than it seems in high school.
I remember thinking in high school "I've got 70 years left in my life, that's plenty of time to accomplish everything." But you don't - you've got maybe 10-15 years (between the ages of 20 and 35) to really make a mark on the world, and then the rest is for raising kids, writing books, passing on your wisdom, and generally enjoying the fruits of those 10-15 years.
(I do reserve the right to change my mind in 10 years and say "Pish-posh. Life's not over at 35 - keep an open mind and you can keep doing cool stuff until the day you die." But this is how it looks from the mid-20s.)