Normaal

is that which costs the environment the least amount of energie.

Geese fly in V-shape thus saving more than 70% of energy when compared to flying alone. http://www.menscentraal.nl/tekst_Theo_Braam_Mundo_Perdido3.html

So when people tell you to "act normal" - step back in line - the group requests to not endanger the savings on group energy.

The opposite of "normal" is authentic.

Being authentic is possible within "normal" life ( i.e. the Buddhist approach of an "unwrinkled life") but one can not be "normal" within the "authentic" existence. Unique means "one of it's kind".

See also Spinoza "in suo genere".