Possible Clues:

• At a rate of one's own choosing (2,4,3,4,4)
• At a personally chosen moment (2,4,3,4,4)
• At a speed of one's choosing (2,4,3,4,4)
• At a moment of one's choosing (2,4,3,4,4)
• At a self-selected moment (2,4,3,4,4)