At t=0 you rarely have 0% of the information and usually you can get more information ahead of starting to jump into the water. The problem is that stakeholders

At t=0 you rarely have 0% of the information and usually you can get more information ahead of starting to jump into the water. The problem is that stakeholders often pressure for early results which prevents enough planning and information gathering. Of course you can also waste too much time on planning and information gathering, but that's not something I have ever witnessed. Usually time is wasted by starting to develop without making a proper plan.