Years ago while doing tech support at a school, I helped a teenager with an issue on his laptop. His assignment was due that day, but the file was corrupted, so his teacher sent him over to the helpdesk to get it sorted out.

I tried to open the file in Word, no dice. I renamed the file to .zip (because .docx files are just zip files with the contents inside), still no dice. I opened the file in Notepad to view the raw contents, and in the header, I saw the letters "PNG", so I renamed assignment.docx to assignment.png.

Staring back at me, was the kid's name, scrawled in his own handwriting using the tiny netbook touchpad, in orange. I turned the laptop around and said "your document was actually a picture with your name written on it. You'll need to actually do the assignment instead of lying to your teacher".

The kid then said to me "I didn't do that. The computer must have done that because I didn't. I just did my assignment and next time I opened the document, it wouldn't open!"

I said "so the computer wrote your name, in your handwriting, in this particular shade of orange, and renamed it to a Word document, overwriting your already completed assignment?". They shrugged and said "yeah", so I said "here's your laptop, head back to class and start working on your assignment, I'll let your teacher know"