I graduated in the top 50% of my high school class and had a 3.2/4 GPA at a state EE program. I hear about high school kids studying 3 hours a day, I don't think I ever studied much more than 3 hours a week. Definitely not stellar academic credentials.
I ended up entering an md phd program where I washed out after 5 years. Fast forward a few years (20...) and I have my own company and will make about $800k-$1M this year.
Yet at no time was I unhappy, even when I was digging for change out of the couch to have enough money to buy food. I remember savoring the ridiculousness of the situation and reveling in it. Yet I'm no happier now than I was at that moment.
Part of life is figuring out what truly makes you happy. For most of us it ends up being bringing happiness to others in some way, not achievement and material possessions.