Through my experience familiarizing myself with my peers, I have discovered that, unlike many of the UC or Ivy schools, there is no concretely defined, quintessential Stanford student. This absolutely enthralls me because it allows me to understand a wide range of perspectives. I have come to know individuals who own multiple companies, immigrated to America with little to nothing, are nationally ranked athletes, are international popstars, have traveled to impoverished countries to promote literacy, and so many other incredible human beings. As long as one is ambitious, for his/her own personal reasons, he/she will succeed at Stanford.
If you are opposed to an extremely liberal lifestyle or have a problem with things like atheism, open homosexuality/transgenders, and other displays of social preferences that are anything but conservative, then you probably won't feel too comfortable at Stanford. Liberalism is the norm at this school and if you openly vocalize your more conservative religious, racial, socioeconomic, or generally conservative preferences, you are likely to face some ostracizing.
Someone who is solely focused on only getting good grades, only building the best paper resume, or only beating everyone else should not attend Stanford. Stanford is a community where peer interaction, education, and support is of the utmost importance - not self-serving and cut throat interests.
Stanford is not for the faint of heart or for people who can't accept challenges. This school fosters your educational development as well as personal development which helps in developing well-rounded people. People just interested in academics and not fun probably might not be a good fit
People who are interested in nourishing the life of the mind won't like Stanford very much. It's an academic school, but most of the academics seem targeted towards career placement or some other utilitarian goal. Learning for the sake of learning is pretty rare.
A person who isn't willing to get involved in the community and take advantage of the opportunities surrounding them (whether it be talking to and learning from other students or attending lectures by prominent figures in society).
Someone hoping to slip through the cracks and "get by" should not attend this university. The school has so many resources and opportunities that it would be a real shame to have it at your fingertips and not take advantage of it.
someone really into prestigious traditions/prestige in general - Stanford's all about pretending it's not prestigious ivy.
Pretty much anybody will fit in. However, if you dont like freedom or being social, probably not the place for you.
A lazy, conservative, close-minded person who doesn't take school or the world outside of their own seriously