The Japanese concept of not comparing yourself to others, drawn from the observation that cherry, plum, peach, and apricot blossoms each open in their own time, in their own way, without reference to each other.
There is a particular kind of ache that doesn't have an obvious name.
It isn't jealousy, not exactly. It's quieter than that. It arrives when you watch someone else reach something you haven't reached yet, finish something you haven't finished, bloom in a season you're still waiting...