Having worked in IT about 12 to 15 years ago I can honestly say I just stopped believing people when they told me they did things or checked things because 99% of the time it was just a flat out lie.
And taking them at their word meant wasting my own time because usually it was just a quick fix that I suggested in the first place.
It quickly, quickly taught me that 99% of people are fucking idiots, and that even the smart ones who actually knew what they were doing with a computer could be idiots too.