I heard from Rav Osher Zelig Rubinstein, Rosh Yeshiva of Toras Simcha in Yerushalayim:
"America was founded on three universal rights as enumerated in the Declaration of Independence: Life, Liberty, & the Pursuit of Happiness.
Life - They have life,
Liberty - they have liberty,
The Pursuit of Happiness - They are still pursuing it!
They will never find it!
True happiness can only be found in Spirituality!"
The fantasy of the Yetzer Horah is only during the pursuit. There is nothing of substance.
Chazal say: "Hirhurei aveira kashim m'aveira - the thoughts of sin are worse than sin". Why? Because the whole test and struggle is only in the thoughts and in the anticipation. The moment that someone actually does the aveira, it loses its luster. He will already be fantasizing what he can do next to fill the void he feels, because that void that never goes away.