Left dominants (people who prefer to use the left brain) excel as accountants, doctors, lawyers, teachers etc. as these professions require mathematical, sequential, logical and linguistic skills, functions of the left brain.

Right dominants (people who prefer to use the right brain) excel as artists, athletes, musicians etc. as these professions require visuo-spatial, motor, creativity skills, functions of the right brain.

Within a specific profession also, there are distinctions. For example, a doctor who leans more towards the left brain prefers to be a physician, whereas a doctor who leans more towards the right brain prefers to be a surgeon. Classical musicians lean more towards to the left brain whereas pop musicians lean more towards to the right brain.
 

Knowing one's brain preference helps one in deciding the right profession and scaling greater heights. Opting for a profession for which one's brain is not wired results in miserable failure, tension and depression.