In trying to explain to a fellow GISer in the office what an HRESULT error looked like, I ran across this link by ESRI.
Per this webpage, (paraphrased): HRESULTs numbers are returned in an eight-digit hexadecimal form or a 10-digit decimal form. The majority of the ESRI ArcObject's error code enumerations are in the 10-digit decimal format. If you have received an eight-digit hexadecimal error code, convert the eight-digit hexadecimal to a 10-digit decimal. This conversion is not difficult and can be accomplished with the Windows Calculator.
So, if in 10-digit decimal format, you can lookup the HRESULT number on a list to find out what the heck the error is sort of about. I haven't tried this, but maybe I'll be able to more than throw up my hands, furrow my brow and stomp off like a two year old when I get and HRESULT error. If this works to reduce my grey hair production, it will be time for a post office celebration trip to conference room Q (or Cue.... a local pool hall and bar).
(ugh - This is starting to look like a Facebook post...)