Nothing profound here, just a quote from Jim Lovell's book "Lost Moon". Gene Krantz was the mission control flight director for Apollo 13. Shortly after the explosion in the service module, Krantz told the mission control team:
O.K., let's everybody keep cool. Let's make sure we don't do anything that's going to blow our electrical power or cause us to lose fuel cell number two. Let's solve the problem, but let's not make it any worse by guessing."
That's what I have to keep telling myself when debugging: don't guess. Hunches are one thing; wild speculation is another.