This quote is particularly near and dear to me.
Many times when I think something will be very do-able, and clearly laid out before me, I will dive in and start "conquering". There are always going to be under-appreciated obstacles (or people) that you will have to navigate through, that will adjust your time-and-space estimate, but it should not alter your vision of getting from here to goal. Keep the clear view in front of you, and focus on sharing that clear view with your team, rather than blaming them for your inability to attain it. ~tb