Like most people I get feelings about things; housing prices will keep dropping, we can achieve a 20% increase in listings count, etc….
However research shows that, we tend to ignore historic data. We are not only overconfident and optimistic, but we also do not consult statistics of similar cases, even if we have access to that kind of data.
The “planning fallacy” (coined by Nobel Prize winner Daniel Kahneman) makes us miss budgets and plans, even if we have the means to use available data to make better estimations. We even ignore the fact that projects have failed. Basically, we estimate based on our current perception, without looking at past data that may provide another view.
Even if we look at past data, we tend to ignore it — again — because the case is “different” and we feel that we know better. The cases from which the statistics were derived are not similar to our case with better people, better defined requirements, better technology, etc.
We overlook data, and we do not trust it. Instead we humans prefer to operate based on intuition. This may work in life-threatening situations as coming across a mountain lion. It does not work when we try to plan and estimate.
For example, in a process like setting up service levels; responding to support requests from customers, most of the time organizations define levels without any guarantee if these levels can be met. What happens if more customers need to be serviced?
So my advice to you, spend time ensuring the data is correct and then trust it. Leave the feelings for the carpet color.