My father—methinks I see my father—
Where, my lord?
In my mind's eye, Horatio.
I saw him once, 'a was a goodly king.
'A was a man, take him for all in all,
I shall not look upon his like again.
My lord, I think I saw him yesternight.
Horatio:Hamlet Act 1, scene 2, 184–191.
My lord, the King your father.
Hamlet has the most active imagination of all Shakespeare's characters. That he coined the phrase "In my mind's eye" is therefore not surprising—his inner life is vivid, and he surveys it often.
But Hamlet's coinage does come as a surprise to his levelheaded but shaken school chum Horatio. In the first scene of the play, the skeptical Horatio beheld, or thinks he beheld, the ghost of the former king, Hamlet's father. Hamlet's wistful "methinks I see my father" therefore unnerves his friend, whom a producer should probably instruct to whirl about to look for the ghost. Then Horatio, after assenting to Hamlet's idealizing assessment of his father's uniqueness, must break the unsettling news that Hamlet may indeed look upon his "like" again. Hamlet does, two scenes later.