Go ahead, do something impossible.
We must always aim for the impossible; if we lower our goal, we also diminish our effort.
You have to set goals that are almost out of reach. If you set a goal that is attainable without much work or thought, you are stuck with something below your true talent and potential.
It's hard to drive at the limit, but it's harder to know where the limits are.
Ever since there have been people, there have been explorers, looking in places where other hadn't been before. Not everyone does it, but we are part of a species where some members of the species do, to the benefit of us all.
When we started Skype, if you look at analyst reports, no one forecasted it as a big business. Also when Google started, it was not fashionable to be in search. It's not trying to do the obvious - that's the hard part.
You can't get anywhere in life without taking risks.
Accomplishing the impossible means only that the boss will add it to your regular duties.
