Stress is caused when you think that a situation should ultimately be changed yet in the short-term you are powerless to change it.

An activity is a hassle when you think it ultimately doesn't need to be done yet in the short-term seems necessary.

Changes in perception can alter your feelings of stress/hassle. If you realize something is ultimately necessary and doesn't need changing, then the stress can evaporate. Or you may see that the situation or activity wasn't what you thought it was, so there's nothing to be stressed about. Or perhaps you find a way around the situation or activity.