I guess the Reagan quote was too confusing for you to understand.
10:2 A wise man's heart [is] at his right hand; but a fool's heart at his left."Right ... left": This proverb is based on the fact that, commonly, the right hand is more deft than the left.
The right side of the body has always symbolized the spiritual side of mankind. The left hand speaks of his earthly nature. A wise man will let his spirit control him, and not his flesh.
2 examples: Jesus sits at the right hand of God; Sheep to the right and goats to the left.