I got a student job at that company and one of my first tasks (and that of several students before me) was to open measurement results on the device and type them into excel spreadsheets. I did this for an hour or so until I became totally bored so I started to tinker around. The measurement device had it's own PC that booted Windows (I think it was 95 or 98) and autostarted their software in full screen/some sort of . This was easy to bypass via the task manager and running explorer.exe. I found out that the proprietary file format was simplay an MS Access file with a different extension. I tried to open it, but the file was password protected. At this time I had little to none experience with programming or anything else that was "low level" computer stuff, but I occasionally stumbled about writeups about hacks and exploits and skimmed over them. So I was pretty sure that there had to be a hardcoded password somewhere. I started to open every file I could in a text editor with no luck. Then I got a hex editor and opened the binaries and finally, in a dll there was a password. The next few days at this job I spent teaching myself enough Python to read the Access files and write the contents into an Excel file.
This worked and I used the free time to study/eat/sleep while getting paid for it but then one of my supervisors found out that I wasn't doing anything but still got results and wondered how I did it. He immediately put me onto another problem they had, thus starting my career as a software engineer.