"A believe that is not true: a false idea or belief that is caused by mental illness"
That is
Considering the definition, it's a disease perhaps a psychological disorder.
Let us ask who is suffering from this illness?
No one would admit it. And they have never suffer from it in anyway.
But the truth is "most people are a patient of Delusion". and the people found in the category are mostly "SUCCESSFUL PEOPLE".
I believe this may be trigger your reaction opposing this view at this junction, but endeavour to read further.
Before i proceed, let me quickly shed light to something.
Delusion should not be confused for Megalomaniac - A condition or mental illness that causes people to think that they have great or unlimited power or importance (Merriam webster)
There is a significant difference that disapprove of the latter.
Most successful people i've seen are somewhat genius. They do not reason within a normal human tenacity. They are crazy and not feeling too well. 
A normal person does not like to stress himself. He doesn't like to take risk.
One who wants free goodies, gifts, etc is a considered a normal human. But they are mostly the ones that beg for things.
They work to serve the abnormal ones. It is not wrong to serve others but severity matters.
Successful people do things that doesn't really make sense to a whole lot of people. This makes them exceptional with extraordinary disposition. Their beliefs and ideas appear very untrue even when implemented. Isn't it a mental illness to take steps that are very risky? For instance, the idea behind steemit as a platform is still very unreal - how and where the money comes from? With the immense populations on the globe, the higher number of people that rejects are far above those that accept it aside for the uninformed. Dan larimer is not normal. Bill gates's idea is still a jabberwocky. Warren Buffett suffers from delusion and so on.
Success is for people with delusions not megalomaniacs. I'm not writing this for sarcasm. If i receive brickbats, then it's as good as what i thought. If otherwise, it is still what i thought.
Thank you for reading
