In the story of Walter Mitty, Walter daydreams wherever he goes. For example, when he was driving, He was daydreaming that he was the pilot of a hydroplane. The wife shook him out of that dream when she said that he was driving too fast. Also, when he went to the hospital He helped out but while he was curing a patient, he started to daydream again.
I think that the wife may be undermining Walter because she tells him to put on his gloves and he does but once she leaves, he takes them off. The wife also told him to get overshoes when he doesn’t want to. She tells him that he is not a young man any longer so he should get some.
I assume that is ok to daydream but try not to daydream while you are doing something that can lead to something bad. Such as daydreaming while driving a car or helping a patient.