you are free to explore anything that you decide is best for your growth and development.
The freedom to stick one's neck out and push the limits can sometimes backfire. For my son, a risk-taker, Brown is ideal: He was advised not to take four calculation-intensive courses at once (math/physics/CS). He was also advised not to take a 5th class in his first semester, while he's getting acclimated. So naturally, in his first semester, he's taking four calculation-intensive courses and
a 5th class with multiple long writing assignments.
I don't expect worse than the occasional hiccup when he has to stay up to 2 a.m. to finish all his work -- and I did convince him to take the writing class S/NC so he would feel comfortable limiting his research (which can become a black hole of time as one explores tangents to tangents trying to write the "perfect" paper). But he really doesn't care if he finishes his four years with a 4.0; he's there to explore.
There are many, many students who tried so hard to get into elite colleges that they stopped taking risks, because that lone B might take away valedictorian status and a 3 or 4 on an AP test might show indication that you are not the best of the best.
Brown is especially well suited for risk-takers, the independent travelers. But there are lots of people who want to take the package tour (aka core curriculum) because it's safe and predictable.