I think that depends on a lot.I went to a huge high school. There were 4000 students- I would only say that “I went to high school with someone” if they either graduated the same year I did (or were supposed to) or if I actually knew the person. And I knew a lot of people who weren’t in my grade both because of the way my high school was set up and because I was involved in activities. By “the way my high school was set up”, I mean there was no such thing as 9th grade English or 10 grade social studies. We had certain requirements to graduate but how and when we met those requirements was mostly up to us. My English course could have had students from 9-12 grades. There were certain courses with pre-requisites but even those weren’t restricted by grade - you had to take Spanish 1 before Spanish 2 but you could have taken Spanish 1 anywhere from 9-11 grade.
Not all schools are like that - at my son’s school every 9th grader took the same classes and so on. The only difference was that some were in honors classes. Even gym was divided into 9-10 and 11-12. So a kid in that school likely wouldn’t know anyone who was a junior or senior when they were a freshman unless they were in extracurriculars together.
I went to a small high school, probably about 220 students in grades 9-12. In the four years I attended, I knew everybody in every grade. My sister was a senior when I was a freshman; yes, I went to high school with her. Likewise, the neighbor boy was a freshman when I was a senior, and I went to high school with him.
I went to high school with all kinds of people. Some were a year or two ahead. Some were a year or two behind. Never mind, I went to high school with all of them.
My sister was four years behind me at high school. I went to school with Sis also.
I ‘went to school with’ Steve Harris out of Iron Maiden, and even shared a few classes with him.
‘At my school while I was there’ was Jonathan Ross, and I knew who he was (he was already appearing in adverts by this stage) but I never spoke to him (although I did interact with his older brother Paul, who was in my year).
Another celebrity who ‘went to my school’ was Derek Jacobi, but that was before I was born, so I didn’t ‘go to school’ with him.
I barely had friends in my own class. My best friends were all in other classes. We all went to school together. I’d been in school with some of them since junior high, and some since elementary school.
Now, there was one I went all the way through school with, from kindergarten to graduation, save for the one year I was in the Soviet Union. But she was the only close friend I had in my own class.
Oddly, we only ever had one class together. I had more classes with some friends who were in other graduating classes. I had lots of classes with people in my class who were not friends. There was this one girl who’d been in my class since junior high, and we were always ending up in classes together-- it wasn’t that we disliked each other-- we just had nothing in common, and hardly spoke. But I ended up sitting right behind her at graduation.
Funny, when it was over, she gave me a hug, but that was the last time I saw her. And most people in my class, for that matter, but I’m still in touch with several of the good friends I went to school with.