That first semester is a big culture shock for a lot of students. They are away from home for the first time, away from friends and family, living with and surrounded by strangers and the coursework is a lot harder. They may get to college and find that they aren't one of the "smart kids" anymore, so depression tends to set in when they are working harder, but getting poorer grades. It's a huge adjustment. Some parents (often Asian parents) tend to pressure their kids to achieve high grades so they can become doctors or engineers (or whatever the parents consider an acceptable career), which is another cause of stress. I do think it's unfair to expect students to make all A's or B's that first semester, but if you are hoping to attend medical school or a top law school someday, that's what you'll have to do.