So, nobody was talking about behavior in high school before, not even you. The message from the post I quoted was pretty clearly that attendance policies in college are ridiculous because kids at an esteemed Top 25 school are so amazing and motivated that they are above the need for such things. But to help you save face, let's pretend that you were totally talking about high school habits.
I skipped my fair share of classes and half-assed more than my fair share of assignments/tests-- pretty much did the bare minimum necessary because I knew I was pretty darn smart and could get away with it. That attitude almost did me in once I got to college and became a much smaller fish in a big pond. But it was a top school and I still knew I was the ****, just not at the top anymore. Then I got to med school and began to get my ass kicked regularly by kids who not only went to state schools, but directional state schools!! How was it possible?? Could it be that one's undergraduate background wasn't an instant marker of their intellectual ability?? Could it be that someone who went to a lesser school could be more hard-working, or just plain smarter than I was?? By the time I got to residency and was consistently outperformed by graduates of (gasp!) state medical schools, I had fully realized that maybe the name brand wasn't everything.
I survived the ego hit, and you will too someday. Good luck!!