This also is not true detachment. As soon as the baby is born, suppose she has a girl, she immediately wants to get a boy the next time. A similar situation develops when someone does not get his wishes fulfilled. Here also he develops a certain type of detachment. All these attitudes are temporary.
Permanent detachment is something quite different.
Permanent detachment is an intense detachment, as opposed to dull or weak detachment. For example, a person may have resolved to go on a pilgrimage to one of the holy places in India, but then there may be a strong tendency to postpone it to the next month. If it is a matter of doing something good such as going on a pilgrimage, one will tend to postpone it. On the other hand, if it is a matter of doing something bad, one prefers to do it right on the spot, without wasting any time. People usually will not make very great efforts to perform good deeds.