Is true that all genious were nut?  

I think that just because someone sees things differently, it does not make them crazy. Saying that all artists or all genius' are crazy is quite stereotypical. Just because someone thinks differently than you, does that make them crazy? No, because if it did, then basically, that is saying that everyone is crazy. Everyone has different views on something, otherwise we would all be robots, programmed with the same ideas and information.

genius

seems when u look at it several people come to mind that are both considered genius and have mental health issues. I think that there is couple different reasons for this.
one
pressure. overall most people of high intellegence are under a lot of pressure to use their gift. both profesionaly and family builds on that pressure and sometimes set unrealistic standards. often leading to what most people would concider a burnout.

outcast
In many situations people of this stature are often an outcast form early age, peers are jealous, or parents wanting to devolpe thier childs intelect make choices that remove person for social settings. without devoloping around others they devolpe in own ways. many times without the life exeriance that would shape the minds and lives of people there own age. esp seen in puberty and teenage years.

could go into more but have to get back to work

I dont think that all genius are nut. They are just more than usual people.
Let's say thomas alva edison, he was bright scientist businessman at that time. He was so creative to discover something great, only from simple think. His discovery bring our life for something "hi-tech". Without his discoveries, i bet you will have many cartons of candles in your house that could be enough for a week. People at that time, also thought that he was a real nut...!
Or lets say, cellphone. at first, idea about wireless telephone seemed "weird and impossible", but few years ago those "genius" in technology proved it... from imaginations, comes the real life... we even wonder, many cellphones now with digital camera and 3G (we never think that cellphones now have more creatures... oh mg! camera4mp in cellphone? have you ever wondered about it?).
So if you're using cellphones, laptop, pc, speaker, calculator, other electronic appliances, all those are came from the mind of genius that you said "weird", and because you're using the product from "weirdo", maybe you're more than weird. How could you're using product from a weirdo, even you think they are weird????

those weird people are just have "more talents" "more thinking" than other people. Become a genius is really "great". And talk about van gogh... that weirdo artist original painting really cost million dollars!!!

Genius brain is terrible EXPENSIVE!!!