What does a hair on the left shoulder mean?

No warning.

Under normal circumstances, a hair growing on the left shoulder has no special omen or symbolic meaning. The distribution and growth of hair on the body are determined by various factors such as genetic factors, hormonal levels and personal physiological characteristics, and do not have special predictive significance. Therefore, a hair growing on the left shoulder is usually regarded as a natural physiological phenomenon and does not have supernatural or omen connotations.