How does your one action affect others? If you cancel a meeting at the last minute, who else does this affect?
Did the people you canceled the meeting with have to rearrange their schedule to fit you in and thus inconvenience all of those others? Were there other people waiting for the results from that one meeting and now not be able to get the results? Were the other people going from your meeting to another one and thus have to make other plans for the next meeting?
When making last minute changes to plans make sure you take into account everyone it might be affecting.
Have a great day!