  The excitation factors of black hole quasinormal modes quantify the
$\textit{ease of excitation}$ of the quasinormal modes and are independent of
the source of perturbation. We compute the excitation factors of Kerr black
holes up to the 20th overtone and find that the 4th, 5th, and 6th overtones
have the first three highest excitation factors for intermediate and high spin
parameters. This provides an independent confirmation of the importance of
overtones that has been confirmed by the fitting data analysis of numerical
relativity waveforms beginning around the strain peak amplitude.
