In high school (in Australia), I went to Year 7 and 8 at one school, and did not do well (ADHD+"gifted"), and spent most of my time, it felt, in detentions, etc.
Moved to another school. Half a term of Year 9 and I was in 10. By the second week of second term I was in Year 11, and went on from there, graduating effectively 2 years early.
Canonical recruiter: "So you don't have any Year 9 grades to share? Or Year 10? Hmm, I'm not sure how we handle that, as we want to know those."
"Amusingly", when I went to do paramedic studies at a Community College in the US, high school graduation was required. Because my high school was overseas, they had to use a "translation service" to validate that my Australian high school graduation was "educationally equivalent" to the US. Never mind that whether or not it was (and I'd argue it was superior), "What about the fact that I have a B.S. (Hons)?". "Sorry, School of Health rules says we need this document for admission". (I got in, but the delays meant I had to wait until the next intake).