Friends:

What does it really mean to be Perfectly Self-Enlightened?

The Blessed Buddha once said this:

Those who do not understand Suffering
Who do not know how Suffering comes into being,
Nor where Suffering ceases without remaining trace!
Who do not know this Noble Way & unique Method,
Which leads straight to stilling of all Suffering!
They are indeed lacking all mental release;
They are neither released through understanding;
Thus Incapable of making an end, stranded, helpless,
They tumble on in birth, aging and eternal decay...
But those who do understand this Suffering,
Who also know Craving as The Cause of Suffering,
And where Suffering ceases completely,
Who understand This Noble Way and Method,
Which leads straight to The End of all Suffering!
They are endowed both with mental release;
And also released through understanding!
Being thus ready and able of making an end,
They stop tumbling on in birth, aging & decay...

It is because one all alone has fully awakened to these 4 Noble Truths as
they really & actually are, that the Tathagata is called a worthy Arahat,
is called a Perfectly Self-Enlightened One, is called a SammāSamBuddha...
Therefore, Bhikkhus, an effort should be dedicated to really understand:
All this is Suffering! An effort should be made much of to truly comprehend:
Craving is the Cause of Suffering! An effort should be cultivated to realize:
No Craving is the End of Suffering! Effort should be made to break through,
reinforce, and develop: This Noble 8-fold Way which Ceases all Suffering...
 

Comments:
Only a SammāSamBuddha can rediscover & teach these Four Noble Truths!
 

More on these 4 Noble Truths (Cattari Ariya Saccani):
http://What-Buddha-Said.net/drops/IV/Ignorance.htm
http://What-Buddha-Said.net/drops/IV/Actually_So.htm
http://What-Buddha-Said.net/drops/IV/True_Wisdom.htm
http://What-Buddha-Said.net/drops/IV/Four_but_One.htm
http://What-Buddha-Said.net/drops/IV/Clustered_Truths.htm
http://What-Buddha-Said.net/drops/IV/The_Ultimate_Fact.htm
http://What-Buddha-Said.net/drops/IV/Simple_yet_Complex.htm
http://What-Buddha-Said.net/drops/II/The_4_Noble_Truths.htm
http://What-Buddha-Said.net/drops/IV/Sour_Sense_Sources.htm
http://What-Buddha-Said.net/drops/II/The_1st_Noble_Truth_on_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_2nd_Noble_Truth_on_The_Cause_of_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_3rd_Noble_Truth_on_The_Ceasing_of_Suffering.htm
http://What-Buddha-Said.net/drops/II/The_4th_Noble_Truth_on_The_Way_to_End_Suffering.htm

Source (edited extract):
The Grouped Sayings of the Buddha. Samyutta Nikāya. [V:433]
section 56: Saccasamyutta. Thread 22-3: Kotigāma & Perfectly Enlightened ...

Perfectly Self-Enlightened!