I found this here, it's a really good paper that backs the idea that goals are pretty tough. http://hbswk.hbs.edu/item/6114.html http://hbswk.hbs.edu/item/6114

I found this here, it's a really good paper that backs the idea that goals are pretty tough. http://hbswk.hbs.edu/item/6114.html http://hbswk.hbs.edu/item/6114.html https://news.ycombinator.com/item?id=7897662 https://news.ycombinator.com/item?id=7897662