And everyone is unprepared for college (as they were for high-school, or elementary, or kindergarten, and especially for their first job). The difference is in how they approach it. Personally, I locked myself in the library until I could do Calculus problems blindfolded, and then went to the bar to celebrate with my friends. Your results may vary. Note that feeling persecuted and defeated after you flunk a Calculus test is not a viable solution.
Sorry for being harsh.