Because the amount of stress determines how much you feel the need to do something*:
70% stress: a state of crisis → “I urgently need to change something, I cannot be calm”;
20% stress: a usual state → you do tasks at your usual pace;
0% stress: a state of euphoria → you cannot even think about anything, you simply exist, and that already feels incredible.
That is:
circumstances changed → the person felt more or less comfortable → the need to do something became bigger or smaller.
*Exceptions are situations in which the circumstances are so difficult that a person has no chance to recover even a little: long-term depersonalization, the highest degree of apathy / depression, etc.