By watching student's 25 years younger passing exams without actually studying them (if I'd do that, I'd bascally failed; I've tested that approach :-))
Not to minimize your own feelings/experience, but I wonder too if younger students are just so much more exposed to the technology that you were being taught that they only needed to learn half the 'net new' information you did.
For example, I went to school for a video game programming/design B.Sc. First couple of years were super basic programming to get non-programmers up to level, so to any of us who programmed since gradeschool it meant no studying/effort for a year while we breezed through simple loops/conditionals/Java stuff.
Obviously, things cranked up a notch when we finally got to new material.