What if you never figured out which ones were your lucky underwear? You would go through life having good days and bad days, randomly pulling skivvies from the drawer, never knowing you could have exerted any level of influence on the outcome of job interviews, dates, sporting events and other pivotal events in your life.
Right now, start studying the correlation between your undergarments and the kind of day you have. Chart it! Mark the appropriate garments! Think what might depend on it: your very destiny.