Have you ever missed the deadline for an important grant application, or come late to a meeting with a new client? The truth is that there will be times when you feel you have made a mistake that will severely disappoint your boss. The good news is that you can always say you are sorry. The bad news is that some bosses make your life miserable for even small mistakes, and it can be challenging to keep things in perspective.
One way to approach this issue is to use your boss’ reaction to the mistake as a measure of the strength of the relationship. If your boss is unable to remain supportive of you despite minor (or even more major) errors, this may be a sign that the relationship is eroding. You then face the choice to try to rebuild the relationship (e.g. talking to your boss about how the mistake might be prevented in future), or eroding the relationship further (e.g. by avoiding your boss each time you think he might disapprove of you). The important principle to bear in mind here is that each interaction you have with your boss either serves to build or erode the relationship. You face the choice to erode or build the relationship whenever you feel frustrated with your boss.