On the subject of that elusive perfect happiness, Ibn Hazm says:

29. When a man is asleep, he leaves the world and forgets all joy and all sorrow. If he kept his spirit in the same state on waking, he would know perfect happiness.

Notes:

• Allah says:

إِذْ تُصْعِدُونَ وَلاَ تَلْوُونَ عَلَى أحَدٍ وَالرَّسُولُ يَدْعُوكُمْ فِي أُخْرَاكُمْ فَأَثَابَكُمْ غُمَّاً بِغَمٍّ لِّكَيْلاَ تَحْزَنُواْ عَلَى مَا فَاتَكُمْ وَلاَ مَا أَصَابَكُمْ وَاللّهُ خَبِيرٌ بِمَا تَعْمَلُونَ


{(And remember) when you ran away (dreadfully) without even casting a side glance at anyone, and the Messenger (Muhammad SAW) was in your rear calling you back. There did Allah give you one distress after another by way of requital to teach you not to grieve for that which had escaped you, nor for that which had befallen you. And Allah is Well*Aware of all that you do} (3:153)

In arabic, it doesn't quite say "to teach". That's a bit of an embellishment on the side of the translators. The arabic word comes out to "لِّكَيْلاَ" which would translate to "so that they may not...". The لِّ starting the word, per the rules of the arabic language give purpose to the word. Before I confuse myself along with you, it basically means this; the events which took place, took place for the purpose of teaching the companions to not grieve for what escaped them nor for what befell them. That's how important an issue this is.

• This attitude is one carried by the salaf. It was said that if you had placed a rock of gold in their palms, or a rock of mud, they would react in a similiar fashion. Meaning, they would not get extremely happy for the rock of gold, not increasingly sad for the rock of mud.
• One could argue that closing the doors to all joy and all sorrow is an exercise in futility for human beings. That may very well be true, however trying to limit these emotions would probably lead to contentment.
• Contentment is all we can hope for in this world. Paradise, and only paradise, is Dar as-Sa'adah (the abode of happiness).