I had my first sim since HSY released go to high school, and it was painfully boring. That pack had so much potential, yet it didn't live up to the expectations for me.
I feel like graduation has always been buggy, as well as most other HSY events. But again, I've only played it when it first came out, and am just now revisiting it. If I'm not mistaken it does require the other sims to have aged up to young adults before they graduate. So if they're still teens when your sim graduates, they won't be there.
As for skill gain, I mentioned this in another thread, but one of my sims gained parenting skill (level 3 through 9) in a matter of a few real life minutes. I chalked it up to him being an alien or a genius at the time, but after reading the thread, I realized it may be a bug.
