Thirty years ago I was living in Japan and was newly married. My husband was a keen member of a hot air balloon club and had his pilot's licence. So he asked me to knit a sweater with a balloon on it for him.
He drew the balloon and I had photographs as well so I managed to come up with a reasonable chart.
At that time, though this was a remote area of northern Japan, there was an extremely good yarn shop, with a surprising range of foreign yarns. And they had vicuna yarn (I should explain that this was well before there was any suggestion that vicunas were endangered). In those days, vicuna was just another exotic yarn, and not even especially expensive.
So I bought my vicuna yarn and settled down to create the sweater. It was probably the first one I knitted without a bought pattern and I remember struggling with it, taking it back and trying again until eventually we were both happy with the result.
He wore it a good deal at the time, but then we moved to Tokyo, where the winters were not nearly as cold, and it got put away. It moved to England with us and eventually to London. But then recently he discovered that vicuna is now a luxury yarn. So he got it out again and wears it to go shopping in on his days off.