A friend once told me that I was a mile wide and an inch deep. The truth is he meant it as a criticism, I took it as a compliment. I know a bit about so many things and I am not the authority on any of them. To me that is a good thing.
In the 1961, science fiction novel, Stranger in a Strange Land written by American author Robert A. Heinlein, a Fair Witness is an individual trained to observe events and report exactly what he or she sees and hears, making no extrapolations or assumptions. An eidetic memory is a prerequisite for the job, although this may be attainable with suitable training. In Heinlein's society, a Fair Witness is a highly reputable source of information.
I can't claim an eidetic memory, but I have got the ability to recall information that affects the situation at hand, often saving or making my clients profits that might have been missed without my presence.
In this role I function as an advisor, listening but rarely participating in vendor presentations and decision making meetings and advise the principles, after the fact, of my observations and information that may be pertinent but was not brought up in the meeting.
I never take a position in this arrangement where I profit from my service beyond the hourly rate charged, no commissions, kickbacks etc. This generally renders a certain comfort in my clients minds that they haven’t missed key issues and have an unbiased party in the process.
If you have ever wondered why everyone has an angle and there is nobody you can trust, trust me, I think you will find it a delightful experience.