Its natural, when there is no clear way forward, when expectations are thwarted we automatically think there is something wrong and we could have done better.
That is why purpose is so important, what we get attached to are the means by which we achieve our purpose and think the purpose is under threat, which is not the case at all, it just means another possibility is required and it will probably be a better way, why? Because we think first of the easier ways which are simply re-cycled solutions from your past, when you find they don't work we often feel angry or lost or blame ourselves for not being good enough. Now is the opportunity to be far more creative.....and find new possibilities.
That’s why in Lean, we have more than one countermeasure when we are looking for solutions, we force ourselves to look for solutions beyond the obvious. We must not be attached to any countermeasure, if one does not work you already have a plan b, but remember the purpose remains constant even if your means of achieving it have to change.