Here are the type of things I've run across in my thirteen years working with college students. Now mind you this doesn't apply to all but it applies to a wide variety of those I have dealt with...
-can't balance their checkbook
-can't follow basic instructions
-can't read at the college level
-can't write the basic five-paragraph essay (which is taught in freshman comp!)
-can't count change without the aid of a computer
-can't do simple math without a calculator
-can't make it to class on time
-blame everyone else for their poor grades
-use "I didn't know" as an excuse for parking illegally, incurring late fees for not registering on time, not turning in papers on time, or cheating.
-can't comparison shop prices in the grocery store
-female students attempting to dress provocatively to get a higher grade
-talking on the cell phone in class and in private offices where people are working
-talking in class while the instructor is trying to lecture
-asking others to take care of their "official" business (like filling out important forms required to GRADUATE) because they decided to go out of town with friends and can't get to it.
If they don't have common sense at this point in life, I don't know that it will ever happen...