Generalist versus Specialist
A generalist is a person who knows less and less about more and more until he/she practically knows nothing about everything.
A specialist is a person who knows more and more about less and less until he/she practically knows everything about nothing.
Optimist, Pessimist and Realist
An optimist sees a glass as “Half full”.
A pessimist sees the same glass as “Half empty”.
A realist tries to figure the direction (of the water) before commenting as either “Hlaf Full” or “Half Empty”.