Context: LaTeX is a typesetting system. When compiling a document, a lot of really in-depth debugging information is printed, which can be borderline incomprehensible to anyone but LaTeX experts. It can also be a visual hindrance when looking for important information like errors.
If you work with LaTeX for five years and still have no idea what a hbox is or what that message means, you should not consider naming this "experience".
Ok, go on then, tell the class what underfull hbox is. And no googling!
I already explained this in my post of yesterday in this thread. I've been the TeX admin at our university in my student times. I've been creating styles and \shipout macros. I know this stuff inside out. Heck, I've even read good parts of the source to understand some finer points.
And you're expecting everyone to have this amount of experience?
But of course, how else could you describe yourself as having experience with TeX? /s
I think our TeX savvy lemming here confuses a knowledge level in the expert/consultant sphere with "having experience".
Having worked with LaTeX on and off for 15 years, and on occasions developing TeX macros (ie copy pasting stuff from stackoverflow and shotgun debugging it until it sorta works) and creating various graphics with PGF/TikZ, I would describe myself as having extended experience with the TeX environment. But I still can't tell you exactly what causes \hbox underfull without looking it up... Probably because it's never caused a failure to output my documents.
Yes? Experience and skill are good things and should be encouraged!
Well, you can use a tool, and acquire just enough knowledge to use it without too many accidents. And then simply give up on progressing any farther. Or you can keep digging into the mountain of knowledge to improve your skills farther and deeper. It is always your choice.
"Using LaTeX" and and "programing with LaTeX" are very different things. For most people, LaTeX is a means to an end, for you LaTeX is your whole job. You're the exception, and exception can not be an example.