... by one careful owner

These remind me of art classes at school where we always seemed to be given things like this to sketch. I was rubbish at it and so I dropped art at the first opportunity. But thinking back on it we were never really given any guidance on how to draw. Contrast that with sums where it would have been unthinkable for the teacher just to say find the area under the curve defined by the function ... without first explaining some principles.

Sic biscuitus disintegrat - as we would have said in Latin class.

Not all of this is true.