My son isn't schooled but I was accelerated when we moved states in high school (here in Australia) and I skipped grade 10. Interestingly the reason wasn't because I was identified as gifted (even though I do believe I was indeed gifted school totally failed me on that one), it was simply a confusion in the way the different systems matched up.
The only subject that I suffered in was grade 12 maths. I missed out on covering statistics in grade 10 and this content was built upon in grade 12. Overall I went from excelling in maths in grade 11 down to average grades, however this was in part due to me having zero interest in scoring well, despite my ability. I have no doubt had I been motivated I could have caught up on the missed content had I had the motivation but I was more interested in pursuing the arts at that point. I don't regret taking that direction at all and sort of wish I'd had the option to opt out of maths at a senior level of school altogether as I've not once had to use it, nor do I remember much!
