In the summer of '99, when I was 11, my father asked me to reverse engineer a proprietary data format because he would be needing that a couple of months later. He showed me how I could manipulate the data using the proprietary software, and how to inspect the changes using a hex editor. It went very slow, and I'm sure answering my questions and explaining it cost him more time in the end, but I learned so much at a young age and he was really happy with the results. Knowing that it was actually useful made it all the more interesting for me.

If I recall correctly he gave me 100 guilders (about $50) for a couple of days of work. The data format was for HP ChemStation, good memories.