Desire

Never satisfy with existing pleasures;

Always crave for the untouchables.

Positively speaking, it's this emotion drives to move forward, even it's tough and hard.

Negatively, why can't I just stay in my own circle without being allured by exterior fancy world?

It's depressing sometimes, more or less, and even strong enough to tear one apart.

The so-called over-indulgent syndrome, I guess.