- Don't use your emotions when deciding
- Don't eat that much and make exercising everyday a habit
- Don't listen to that school counselor; never EVER go to public school
- Spend less
- Care less about grades more about work
- Don't move to Kayışdağı
- Leave your parents' house before 18
Not that important but it was an then-expensive lesson:
- Don't buy that Samsung Omnia, get the iPhone
- Don't listen to that school counselor; never EVER go to public school
She told me and my family to opt for public school in high school but quality of education was[0] very low and I was already making money as a software developer at that time. Private schools have access; better network for the future and most of them have excellent education.
- Care less about grades more about work
Again, I was in a shitty school that gave me nothing. Working towards a better career would be better choice.
- Leave your parents' house before 18
This is a personal opinion. It was clear that I was going to move to a different city but I've never had to do any chores at home. So, my first year, I failed at some basic tasks in the house since I had no experience. If I was living in a separate house before moving to a different city; somewhere close to my parents, it would've been better.
[0] still very low.
I need to point out that all of these opinions are rare in my country. Combination of a rich family, love for technology, hunger for knowledge and luck is the reason why my opinions are like this.