But seriously, Final Knowledge is necessary for the abandonment of the three poisons. If you'd rather use a different word, you can say Final Knowledge comes along with the total abandonment of all attachments. They are one and the same. The difference is that one can be free of anger, greed, and delusion but not be in the state of Final Knowledge. The other thing is one cannot be totally free of anger, greed, and delusion without having first realized Final Knowledge. This is why. In the realization of final knowledge one experiences the total cessation of perception and feeling through not clinging to anything. It is ones capacity to let go of perception and feelings which enables a person to enjoy the freedom of sensual lust, aversion, and preoccupation or mental attachment. A true Arahant, a person truly free of sensual lust, aversion, and preoccupation can only be "truly free" if that person is able to let go of the mental requisite which conditions the existence or uprising or subsistence or continued ontological being of perception and feeling. Hence, the cessation of perception and feeling is the essence of non attachment to physical objects as they arise in the form of perceptions and feelings. Thence, an Arahant must know this knowledge, but is not necessarily a part of it for his entire existence, though having gone through it his bonds to sensual lust, aversion, and mental preoccupation are cut-off.