From my own experience, I would never say something like, "Those (high school) days were the best days of my youth," but I would also never claim they were (mainly) filled with regrets and sadness.
i do miss those highschool days not the friend nor the study just the comfy that you just live your life day by day and don't have to think abouth a damn thing .
I'm two months away from graduating and I feel the same. I don't love my high school life and I want it to get over quickly. But I hope in the future that I can think back to my high school memories in a positive way