I think it is almost impossible to judge your own business idea correct. Either you are to optimistic because you spent so much time with the idea and became a

I think it is almost impossible to judge your own business idea correct. Either you are to optimistic because you spent so much time with the idea and became a fan of it. Or you shoot all your own ideas down. Also i do think design can be important. But of course it can't help if the problem is somewhere else too.