Being so centrally important, it is great news that we are able to consciously develop our identities. An obvious first question would be; How?
Habit number two of Stephen Covey's 7 Habits of Highly Effective People is "Begin with the end in mind." And if you have read the book, you know Covey gives us an exercise to perform (though I doubt many people actually do it). The exercise is to write your eulogy. Obviously, writing your own eulogy is a way of beginning with the end in mind.
Unrelated to the work of Covey, while speaking with Professor Greenfeld she told me she assigns the same exercise to her university students, because she has found it to be a useful way to cultivate your identity.
Peter Drucker has a similar but different exercise, which requires a less explicit contemplation of your own mortality. Drucker explains that his exercise goes back to at least Saint Augustine, but reveals he first learned of the exercise from economist Joseph Schumpeter. According to Drucker, Schumpeter and Augustine, everybody must answer the question "What do I want to be remembered for?"
To state the exercise in more humorous, and potentially more triggering terms, the French absurdist philosopher Albert Camus advocated contemplating the question "Why shouldn't I kill myself?" In other words, what do we have to live for?
Drucker said if we don't do this exercise we will waste our lives, and Greenfeld has shown how a malformed identity can lead to profound mental illness. So whichever way you look at it, the stakes are high and you should probably do the exercise!