First Aid for Beginners

I've quoted Peter Drucker's Managing Oneself before: that bit in which he says we need to play to our strengths rather than expend needless effort rectifying our weaknesses. He has this to say:

"Most people think they know what they are good at. They are usually wrong."

There seems to be a logical inconsistency: if we are not good at identifying our strengths (i.e. we have a weak ability in this area), why does Drucker tell us how to do improve?

Anyhow, I come to this piece with a 'strength' I now believe is a weakness. I have tended to think myself good at getting to the heart of ideas. If I try to discern objective evidence for such an assertion, I struggle. I can however discern counter-evidence.

One example of my imagining that I've understood something has to do with the concept of a 'wounded healer'. Having once heard the term I believed it to signify that one needs somehow to be wounded in order to be an empathic healer. That's not the whole picture, though: at least not in the sense that Henri Nouwen used it in his book 'The Wounded Healer'.

Nouwen's use is from a legend in the Talmud, in which a rabbi asks Elijah how he might find the Messiah to ask him when he is coming. Elijah replies that he is at the gates of the city, sitting with the poor and covered with wounds. What sets the Messiah apart is, the rest are removing all their bandages at once and re-applying them, whereas the Messiah is dealing with his own wounds one at a time. In this way the Messiah will always be ready to help others at a moment's notice (while others are preoccupied in re-bandaging).

But which wound to tend first? Or perhaps I should start by looking to the functioning bits between the bandages ... like reason.