mechanical analogies yes and I was actually I felt unhappy with functions and not at home with them until I started programming when I was a graduate student yeah as soon as I started programming a function was just a box she gave it one thing and it gave you back something else but until then I had I didn't really I wasn't friends with functions and that made math I got worse and worse at math um can I generalize and say that if you don't understand its purpose you challenge it or dismiss it maybe I'm reaching to to