Your post actually struck a chord with me and I wanted to take the time to respond and share my thoughts.
First of all, I agree that high school is really easy compared to university. I’m kind of in a similar situation you were in because I didn’t learn how to study efficiently in high school, but I did in university. But the reason I didn’t learn how to study efficiently in high school was because of how easy it was. I ended up graduating salutatorian, or 2nd best GPA from my private high school, out of around 14 or 15 people, but everyone else was also really, really skilled, talented, and intelligent so it was a surprise that I even managed to achieve that. My first year at university was okay, but my second was terrible because I had no idea how to manage time effectively. I ended up having to switch majors twice and basically lost almost a year’s worth of classes because I just didn’t know how to study properly. Thankfully now I know how to, and I’m in the right major and everything, but I wasn’t able to learn this until I was in university because the high school I went to basically didn’t help teach how to study properly. We weren’t given homework that often and it was too easy.
As far as the scholarships go, I did manage to get into an honors society which means I’ll only be around $30,000-$40,000 in debt next year when I graduate university. However, in my case and in lots of other peoples’, I just wanted to say it’s entirely possible to finish at the top or near the top in high school grades-wise and still be overlooked scholarship-wise for people that have even more achievements than you do.
That being said, it’s better to not just do your best academically in high school, but also to become involved in activities, clubs, and some of the other programs people have mentioned in this thread. You can be the top scholar in your area academically and still fall short on scholarships if there’s someone else that has good grades and is also well-rounded as well.
Lastly, on the life experiences point, I actually did well in high school and still haven’t really experienced the true college experience. Sure, I live on campus when it’s time to go back to school, but I still live with my parents when school isn’t in session and I also have no means to drive anywhere when I’m both home and at university. I go to a nearby university as well, so I haven’t really been able to experience being on my own as much as I could have had I went to a university out-of-state or in another country.
On that point, I don’t think doing well in high school automatically means you’re going to be able to go to a culture-rich, beautiful, or prestigious university. The university I go to is actually a place where everyone takes their studies seriously and it isn’t that beautiful or anything. Everyone is basically just focused on graduating and either going to graduate school or getting a good job post-grad.
tl;dr, I agree with most of what you said because I’m in a similar situation. I just wanted to provide my own insight and experiences as well.
Don’t focus on just doing really well in high school academically. You have to open yourself up to new experiences, become well-rounded, and also still take time to not get burned out and relax at times as well. Doing your best in high school is worth it, but not to the point where you don’t care about anything other than grades. Trust me, I learned that the hard way.