“Persistence and obstinacy are enormously important and Jews have been known, and are alternately proud and not proud, for being hard-headed and unable to move.
Determining which things are important and which are not is the essence of life.
They may be your family, your environment, your chosen way of life.
The ability to be persistent and to go on and not allow yourself to be diverted is important here.
On the other hand, if a person becomes obstinate about any kind of little thing, then it is basically damaging.
So I have to decide that I will be obstinate only about important things”
–Rabbi Adin Steinsaltz
From We Jews, p. 78, by Rabbi Adin Steinsaltz