it's human nature.

human nature has never been stated so boldly and straightforward.

"What win I, if I gain the thing I seek?
A dream, a breath, a froth of fleeting joy.
Who buys a minute's mirth to wail a week?
Or sells eternity to get a toy?
For one sweet grape who will the vine destroy?
Or what fond beggar, but to touch the crown,
Would with the sceptre straight be strucken down?"

-The Rape of Lucrece, William Shakespeare.

simply put is our favorite cliché statement, we always want what we can't have.