I am something everyone searches for
No matter who you are,
Deep down, you crave me.
I can make your sun shine
Or I can bring you grey clouds
I can make you feel high
I can make you feel on top of the world
Like nothing could ever harm you,
Like you're invinvible
Or I can tear you down so low
I can make you do things you swear
You'd never do
I can turn the strongest people weak
The bravest people into cowards
I can be the reason behind your smile
When you wake up
Or I could be the reason you cry at night
When your head finally hits the pillow
What am I?