at one's best

Koh delves into the perspectives of characters both tangentially and intimately related to the family, from the guard who oversees Yohan’s torture to a middle-aged businessman and activist for Korean reunification, showing how being witnessed by others is vital at one’s best and worst.

The episode sheds light on the complexities of accommodating mental illness in adventure sports, where taking part even at one’s best is perilous.

Carroll decided to refine his own philosophy relentlessly, eventually distilling it down to an “always compete” mantra that’s less focused on winning than on being at one’s best.

Why, they're all that way, and both Marie and Annita would draw the line at one's best silk stockings, I am sure.

Who does not like to be complimented, especially in the early morning when one is not apt to feel at one’s best?