The realisation that the childhood has ended

So i'm in the last year of highschool and i only now inderstand, that it's my last year of studying in school, being with my friends and stuff. After that it's kinda rought years of studying in university. This is the last time when i can do things i want and just be relaxed. Now when i look back on my early years i understand that i was not doing the things i would like to do, and just spent that time sitting and playing video games. I don't think it was good for me. But i don't feel like i wasted time, it was just spent on something easier and i don't regret for spending that time. I think it even helped me to grow as a person i am today, shape my interests and give me a set of ideas and goals for the future.