Let me preface this article by saying that it is based on my experience at a public school, so this may not apply to everyone. Also, just because I say that public school taught me some invaluable skill doesn't mean I'm implying that you couldn't possibly have that skill also because you went to private school.
Don't think that because I'm a public school advocate I think everyone who went to private school is a prick. We're all sort of pricks, regardless of what kind of school we went to.
Apparently public school kids feel superior when we say, "Well, I went to a public school and I got in here." Well, I went to a public school and I got in here, and I do not feel somehow better than you. The thing is, whether you went to public or private school, you were probably used to being the smartest kid in the room. You had the most amazing extracurriculars, blah blah blah. Let's be honest. Everyone at Dartmouth was that kid, whether it was at a public or private school.
But there are differences that arise from whether you put the stud in student at a private school or a public school.
If you went to a fairly large public school, you are used to being around more kids. My school had just about 2,500 students in all. My graduating class was around 700, more kids than many private schools. Everybody didn't know everybody else, but that was kind of a good thing. Not having people know you super well can have its advantages at times. Imagine if the people in that frat basement constituted your entire high school class.
Having a large school also prepared me for meeting new people that go to school with me. In high school, I didn't feel awkward making friends with people I had never seen before, even in my senior year. Not being forced to know everyone actually kind of teaches you how to meet new people and actually get to know them. (I'm not considering drunk hook-ups as meeting people by the way.)
Having had lots of people in my high school also makes me more comfortable now in the classroom here at Dartmouth. My math and physics lectures only have about 10 more students in each than my math and physics classes in high school. Hurray for California budget cuts! Seriously though, I would be kind of freaked out if had I gone to private school and my Bio 11 class had more kids than my graduating class, or my whole school for that matter.
Having too many kids at a school for the teachers to be really personal with all of us was good preparation, because that's how it can be in college. Or on the other hand, when professors are really close, that is a welcome bonus, rather than something that is taken for granted.
I feel obligated to speak about my school's counseling office. My counselor didn't remember my name for our first three meetings and she hadn't heard of Dartmouth. (I know, right?) I only saw her three times (once a year) until senior year, when it was time for college applications. She was helpful with all of the regular counselor tasks or whatever, but she had less effect on my actual college applications and selection than a handful of websites.
Ultimately, though, this lack of a personal connection was a blessing in disguise because I learned to really take charge of my academic path myself, a habit that has been helpful here.
My point here isn't a sob story about how disadvantaged I was in high school. It's about the attitude I learned. When the state pays for your education, you have to be a little bit independent if you want to succeed.