The average college semester is about 15 weeks, with each class meeting maybe 2x a week. So only 30 classes in a 15 week semester, per class (on average).
In high school, you attend each class every day for 39 weeks. That comes out to roughly 180 classes (discluding weekends, holidays). So missing 5 days is a smaller deal when you miss them out of 180.
I fucking hated high school. All anyone cared about was looks, sports and dating. and who was popular. IN college everyone is more 'individual' rather than group membership (unless you are a fraternaty member), and the freedom is nice. ANyway, i think college should be much different than high school. High school was immature, repressed and slow paced (a semester of material in 180 classes). College is more mature, free and faster paced.
Where i go to college, attendence is mandatory in some classes. The grading scale is built so if you don't attend classes, you lose up to 50% of your grade.