Let me start by sharing a bit of history about myself.

When i finished my secondary school i did not go immediately to high school. I took a year because i needed to improve some grades to enter high school more easily.
In that year i started to learn programming languages (Java).

So when i went to high school i already had a good foundation of programming logic and could make some simple games that my friends were amazed (Like Pong and tetris).
In my first year in high school, in my hometown, a photo frame builder's shop asked me if i could make a desktop program to help him calculating prices and such.

I did it in like 4 months. This was not my biggest projet so far but was the most satisfying at the end. He paid me really good money for it and i was very proud of myself.