Our judgements that we hold onto are riddled with personal bias and a poor understanding of the past - behavioural psychologists have done significant research on this over the years.
We call these faulty judgements 'blind spots' - and as a leader of an organisation they pose the same threat as partial blindness would to an airplane pilot.
In a great example of how to solve this 'blind spot' problem - we can turn our attention to the world of science.
Science has built their entire discipline around the elimination of blind spots. Science does this through a thorough process of falsification. Once a theory has been presented, the job of a scientist is not to prove the theory right, it's to show under what conditions the theory fails.
'Scientific fact' is another way of saying that all effort has been made not to prove the fact right, but to try prove it wrong.
If we had to apply that same level of vigour to other theories - we could do the same with a company / marketing / brand strategy.
The strategy itself is almost irrelevant; what you really want to have is a clear view and understanding of which future scenarios render your strategy useless or risky.
Only then will you really get a sense of how good it really is.