It's mainly my own problem. I have a tendency to "put things where I can find them easily".
In other words, a place for everything and everything in its place. Except that it's rarely the same place twice in a row.
I know the manual is somewhere in the house, it's just the "where" that is in doubt and I need to fix the darn sewing machine or whatever right now. With my Brother CS-100 I downloaded the owner's manual easily, and it is pretty easy to follow. It's just that I'm still having a problem with the tension, the bottom threads are still not staying down unless it's a straight stitch. Probably have to read all the darn thing, and there's a lot of it.