Although Irish author Joyce Cary's "A Special Occasion" involves children, the theme that speaks to me is one that applies most especially to adults.

Tom is a young child of privilege: he has nice clothes, a nursery full of toys and a nanny. Nurse's expectations of the child brook no argument: he is to be polite and give his undivided attention to this guest, Jenny, who it appears he has been asking to play with all week. 

However, Nurse does not give the boy her undivided attention. This is ironic in that she expects Tom to do something different than what she does with him. She leaves him alone in the nursery with Jenny:

Nurse had gone into the night nursery, next door, on her private affairs.

When she finishes her personal affairs, she returns:

Nurse, having completed her private business, came bustling in with the air of one restored to life after a dangerous illness

"Life after dangerous illness" seems to indicate that her vigor is restored and can now return and deal with Tom, who seems quite content to play as he is. And Jenny is equally content with a picture book. However, Nurse believes that she knows what is best for the children, and begins to scold Tom for leaving Jenny alone—which is exactly what Nurse has just done.

The author points out that Nurse is plump, and old-fashioned. This infers that she is older; being plump may indicate that it is not so easy for her to actively entertain Tommy. Being old-fashioned may indicate that she expects the child to be seen and not heard, and/or to follow her directions without question. We can assume that Tom plays as he does because she leaves him to entertain himself as she does things for herself that do not involve spending time with him.

Tom does not see the sense in Nurse scolding him, for both children are doing what they want, and they see it as comfortable entertainment: they are sharing a moment much like adult camaraderie. If these children come from similar households, this may be the way they play at home: alone. Tom denies that Jenny is alone: after all, he's right there in the room with her.

Tom is only five, but he doesn't like to be embarrassed: when Nurse reveals that he has been begging for Jenny to come over, he denies it and becomes angry at her disclosure. But still he doesn't want Jenny to leave. Then he contradicts himself, saying he never wanted her there in the first place!

Violence erupts between the kids; Nurse has to carry a furious Jenny out of the room, while an equally enraged Tom throws his toys about, and howls for a full five minutes. However, before long, with a sense of self-satisfaction, Jenny returns (unbeknownst to Nurse it appears) and joins Tom once more. At first he is still angry, but soon he is playing with "surprise and pleased excitement." Jenny climbs daintily under the table, once again with her book.

The conflict arises between the children because Nurse wants them to "play" as the she expects them to. Tom and Jenny are perfectly happy playing quietly together. Nurse imposes her will on the children without concern of how she can help, but how she can control.

Nurse should let them play as they want. They should be allowed to engage in activities that they enjoy. Left to themselves, Tom plays on and...

...[Jenny] gave an enormous sigh of relief, of very special happiness.

The theme seems to be that people should not try to tell others how to be happy (or live). Only we can find this for ourselves.