...

Life - Death
Love - Hate
Happy - Sad
Friend - Stranger,
Relax - Stress
Win - Loose
Woman - Man
Young - Old
Rich - Poor
Single - Married
Simple - Complicated
Successful - Fail
Play - Stop
Working - Sleeping
Morning - Night
Laughing - Crying
War - Peace
Bright - Dark
.....etc

All things has positive but at the same time it has negative...Its the balance of life in everythings....Nature....