In addition to cleaning bathrooms in high school, I have worked as a skating waitress at Sonic Drive-In restaurants (yes, including hose, black shorts and a change belt), a hostess at a restaurant, a banquet waitress, an ice cream scooper, a telephone switchboard operator (yes, I am old enough to have flipped switches to connect people), a bookkeeper and a seed counter.
I learned a lot: It is important to show up on time and stay until your shift is done or all your work is done, whichever comes later. Not only does the work have value, but so does the worker.
Whether it's cleaning bathrooms or flying jets (which I have never done), if you do a good job and add value to the world around you, then your work has value. It doesn't matter so much what you do, it's how you do it. A valuable lesson for all to learn.