Answer by A Quora admin:
Akshansh's answer is quite in depth and I'd like to add on to it.
Let me first address the question.
Is the Joker actually insane?
What we are looking isn't insanity but instead a form of Super Sanity. Most people who think themselves to be rational, go crazy in the process of trying to rationalize everything. We can't deny the fact, that its the questions we can't comprehend which are the ones that really fuck with our mind (eg. "What is the meaning of life" )
But, The Joker on the other hand doesn't have such questions!
He doesn't have control over the sensory information he receives from the world.
His method of survival is by going with the flow. No real personality, no real character.
He has the subconscious power of recreating himself whenever he wants.
He gives an entirely new outlook to human perception, more in tune with the madness around us! (The world is pretty screwed up)
Hence, The Super Sanity.
In a sense, Joker is a Nietzsche ideal, (read this in another Quora answer) which would also explain his origin in the next part.
How did 'The Joker' come to be?
There are quite a few origin stories and the numerous stories are a result of Joker's psyche.
The Joker, has the ability to forget what he wants, whenever he wants.
He also has the ability to remember what he wants, whenever he wants.
Seems ironic, doesnt it?
'Beasts do not remember; mankind does. Man is an historical animal whose memories weigh down upon him. Happiness is forgetting, though remembering is what gives the man ability to utilize lessons from the past in the present.' ~ Nietzsche
A Nietzsche Ideal. That's exactly what he is.
It is the beauty of this that no one really knows how he came to be? or how did he get those scars? When asked, he gives a different account every time.
He could have been a member of the Redhood. A failed comedian too. Maybe his Dad gave him his scars. Maybe he gave them himself.
We could only debate which stories are true.
An excerpt from Alan Moore's The Killing Joke helps us understand him better.
' Memories can be vile, repulsive little brutes.
Like children I suppose. But can we live without them?
Memories are what our reason is based upon. If we can't face them, we deny reason itself!
Although, Why not?!
We aren't contractually tied down to rationality?
THERE IS NO SANITY CLAUSE!
So when you find yourself locked onto an unpleasant train of thought, heading for places in your past where screaming is unbearable…
Remember, There is ALWAYS Madness.
Madness is the Emergency Exit.
You can just step outside, close the door on all those dreadful things that happened. You can lock them away…
Being Irrational might be the most the most rational thing to do.
Beautiful isn't it?