Being easy to describe can make it harder for people to notice you changing.

A clear description is convenient and slightly imprisoning. Once people have a compact account of you, they stop looking, and changes get filtered out as noise rather than registered as change. The easier you are to summarise, the longer it takes anyone to notice you are different.

If you are trying to change something, saying it out loud to a few people is more effective than demonstrating it, because demonstration alone will be read through the old summary. And when someone you know well does something out of character, consider that your description may be out of date.