How to achieve happy, peaceful, satisfied and contended life?

 It was narrated that Anas (radhi Allahu anhu) has said :

The Prophet (sallallahu alaihi wasallam) said : *Whoever is mainly concerned about the Hereafter, Allah will make him feel independent of others & will make him focused & content & his worldly affairs will fall into place. But whoever is mainly concerned with this world, Allah will make him feel in constant need of others & will make him distracted & unfocused & he'll get nothing of this world except what is decreed for him."*

[Tirmidhi 2389, classed as saheeh by Shaykh al-Albaani in Saheeh al Jaami 6510]