If you actively develop (or are learning how to develop) HTML code, the W3C Validator is an incredibly useful troubleshooting / debugging tool to have around.
I teach an introductory and intermediate course in web design (HTML and CSS) for photography majors. In my classes, I make it a point to have my students use the validator before submitting their code before turning it in. It’s good practice and a better way to learn troubleshooting.
Anyway, that’s the genesis of today’s strip. Maybe you can relate?