Requirements 1-0

We rely on requirements have our designs. Designs are results of processed requirements. that it self shows the dependency our designs relies on requirements. 

so undoubtedly, requirement gathering is the most difficult aspect of software development. Every other stage in development cycle is made difficult by our actions. Specialty of requirement gathering is it contain elements of surprise or/and actions goes beyond your control.

No one is supposed to collect the all the requirements or in a perfect way and it is not human nature to achieve such good results.

But there is one thing that we all can follow on with respect to requirements. Irrespective of whether they turn up to your face before, during or after the cut off date, there could be only two statuses. 0 and 1. 1, you know about it or 0, you don't.

now not hard as it looks right, but it gives you the base line for next course of actions. how do you identify it is either 0 or 1, is just being thorough with the requirements you have collected like no one including the very people gave you the details, should be able doubt you.

biggest danger or risk, a designer would mount on is, developing a doubt about your own work. once let that come to you, everything else would be easily be fallen apart.