A man is a good retainer to the extent that he earnestly places importance in his master. This is the highest sort of retainer. If one is born into a prominent family that goes back for generations, it is sufficient to deeply consider the matter of obligation to one's ancestors, to lay down one's body and mind, and to earnestly esteem one's master. It is further good fortune if more than this, one has wisdom and talent and can use the appropriately. But even a person who is good for nothing and exceedingly clumsy will be a reliable retainer if only he has the determination to think earnestly of his master. Having only wisdom and talent is the lowest tier of usefulness.
That's actually a decent quote to chew on, if I ever find myself in doubt of my tech/security skills.