Happy Pig Theory!
Human = eat + sleep + work + enjoy
Pigs = eat + sleep
Hence, Human = Pigs + work + enjoy
if, Human - enjoy = Pigs + work
in other words, Human that don't know how to enjoy = pigs that work

Men = eat + sleep + earn money
Pigs = eat + sleep
Hence, Men = Pigs + earn money
therefore, Men - earn money = Pigs
in other words, Men that don't earn money = Pigs

Women = eat + sleep + spend
Pigs = eat + sleep
Hence, Women = Pigs + spend
therefore, Women - spend = Pigs
In other words, Women that don't spend = Pigs
Summary: Men earn money not to let women become pigs!
Women spend not to let men become pigs!
Men + Women = 2 Pigs

Wish all the pigs happy forever.