Both in high school and college, my instructors used it. I found it useful and it remains the default go-to mental model for me. Wikipedia even has an article

Both in high school and college, my instructors used it. I found it useful and it remains the default go-to mental model for me. Wikipedia even has an article on it: https://en.wikipedia.org/wiki/Hydraulic_analogy https://en.wikipedia.org/wiki/Hydraulic_analogy