I loved this movie when I was a kid. I bought the VCR tape for my birthday once, and watched it all day.
I just love the plot theme. Billy is sent back to school after his father reveals that he bribed all his teachers to give him good grades. To prove that he isn't worthless he goes back from 1st grade to 12th (for a short time) and to prevent his father's company going to some jerk.
Eric was a decent villain. Snarky and two-faced.
The teacher was pretty hot.
But most of all, cherish your childhood kids.